If you wait until impact before making an emergency application, you risk testifying in court that you wanted to withhold braking until you knew it was absolutely necessary, rather than doing everything possible to at least slow down and lengthen the time for a person to get clear.

Why would they be in court to begin with? Considering that that the party who would be suing was trespassing in the first place, why would they want to go to court and risk that charge?

No thump no dump

Back in the late 70s when Canadian National ran No. 6060 on scheduled trips to Niagara Falls, I recall an incident on the Grimsby Subdivision near St. Catherines with the train probably running at close to 80 mph. There were a couple of boys on a through truss bridge on dirt bikes. They wouldn't move and Ray placed the train in emergency.
There were some tense moments in the cab. The boys skeedaddled and the police were called, but likely nothing came of it.
Luckily, no one was injured and no damage was done to the locomotive or rolling stock.
About the only cure to all this would be secure fences (expensive), restricted access, arrests for trespassing, and meaningful fines. However, in UP's case, that defeats some of what it is hoping to do with the steam program.

Convicting a dead person of trespassing is kinda pointless. The trespasser’s survivors could, however, go after the deep pockets of the big corporation for either negligence for not sufficiently warning said trespasser or some other sort of nonsense. It’s silly, but that’s the way it seems to be nowadays.

The bottom line is that people generally have a "that'll never happen to me" mindset on safety. I work for a insurance company in auto injury claims. You can't imagine the number of people who have no good insurance because they'd always assumed they'd never be at fault for any accident. That happens to someone else, they think. The very idea is insane, but you'll never get that across to some folks.
Someone earlier mentioned Sarge dropping you for pushups when Pvt Elmo does something stupid. I was an Army officer and I went through training on recovering damaged vehicles under fire. One lesson hammered into me was to always stand twice the distance from a cable under tension than twice the length of the cable payed out (In other words, 10 feet of cable from the recovery vehicle to the damaged truck/tank, you stand at least 20 feet away) in case it snaps. In the years since I resigned from the Army, I've since seen people standing less than a foot away from a cable under tension, and I've yelled at them. Each time, they just sneer and say nothing's gonna happen (one guy even said he'd jump out of the way in time if it snapped).

Also, the person shooting the video in question (not the woman who got hit) is focused on the coming train, not looking around at other stuff. That is reasonable and expected.
I am reminded of something I saw from a guy who came with me and my best friend when we were chasing N&W 611 through Florida in the late 1980s (I was a teen, Mark was in his 20s and my pal Bob was in his early 30s. Bob and I had been around a lot of trains, but Mark hadn't).
We were at the Suwannee River bridge at Fargo, Georgia, waiting on 611 on a NS run to Valdosta, a couple of hours early. This is where they usually did the photo run by on those runs, so we knew we could get ahead of the train from there after getting our photos. Mark was not a rail fan but he knew photography and didn't want to be left behind for the day. He didn't want to risk getting in the way of Bob and me, so he went to the other side of the tracks. Bob and I used a large signal box as a base to shoot from.
Soon, a NS freight came. Bob and I snapped our shots, and then we noticed that the engineer was leaning on the horn and we had no idea why. Bob later swore he heard a muffled cry nearby as the six-axle EMD units roared past at speed.
After the train cleared, we saw Mark on the other side of the tracks, much more pale than normal with a dazed look. When Bob asked Mark what had happened, Mark said, "I got the train in my view finder and it just kept getting bigger and BIGGER…" Realizing he must have been in the open near the tracks, we asked where he had been standing.
He pointed straight down, at the end of the ties! Had he not jumped out of the way, that EMD would have been wearing a Mark-colored smear on its pilot when they ended their run! We noticed that Mark was well clear of the tracks for the rest of the day, having by then realized he almost got creamed by a diesel going at Run 8. I recently found the negative I shot of that train, which I really should get a good print of to remind me of that day.

Without getting into some kind of debate, UP 4014 supposedly stopped several times for trespassers on the track in the recent runs. I recall seeing a video where the train stopped short of where the guy had set up the camera and tripod, and a crew member (supposedly Dickens himself) came out of the cab with a bullhorn to admonish the folks before creeping forward to its intended servicing stop.

And based on my personal observations on only two days of operation, if UP 4014 stopped every time there was a risk of a trespasser strike, that train would STILL be making its way back to Cheyenne, and we wouldn't have a UP steam program either as a result of the delays.

Again, I say: The End Times are nigh.
And I blame "smartphones."

Because litigation, and juries "sticking it to the man" have replaced baseball as the national pastime.

My understanding is that there is now a syndicated TV show on daytime TV that depicts supposed personal injury lawsuits in courtrooms, much like "The People's Court" show of decades ago, only it seems every litigant tends to win against whomever they're suing for hundreds of thousands or millions, and they subsequently follow with a brief overview of the case by one of several (apparently sponsoring) personal injury attorneys nationwide, always telling why the suit was a wonderful idea. In short, it's apparently a 30-minute infomercial for the personal-injury litigation industry, masquerading as "entertainment." And this doesn't even take into account juries full of people who can't come up with excuses to get out of jury duty.......

I know for a fact I've been "lucky." It seems that my chance of seeing something worth phoning/radioing in is inversely proportional to my access to communications. Now that we have cell phones and phone numbers at every crossing, well.........

The other things you cite are evidence of such happenings, not the incidents themselves. I've seen my share of unauthorized riders, burglarized containers, nicked signs, etc. In my personal experience, a lot of dangerous situations never make it out of the yard.

And I don't spend much time deep in yards any more checking my "charges." Anyone that does, and/or anyone making a living as a railroader, is going to see a LOT more of this stuff, just as the long-haul pro truck driver sees far more traffic stupidity than the commuter, who sees more than the once-a-week shopping/church driver......

Motorcycle riders that take safety courses are specifically taught that, at some point if they ride long enough, they WILL take a spill and hit the ground unplanned, and are taught how to reduce injury WHEN it happens. It is utterly common sense to teach railroaders and rail enthusiasts about the prospects of dragging equipment, derailments, things falling from trains, etc., because stand trackside long enough and something WILL happen. I just think attempting to present every last passing freight to the public as near-certain death is counterproductive to the PR message UP is supposedly using 4014 and 844 for.

But, then again, I'm a big believer in personal responsibility. My family has been instructed not to sue any RR for my death on a RR property unless bullet holes or poison are involved...... >;-)

Darwin was almost able to make a slight improvement to our species.

It also doesn't take into account that juries often throw such things out of court.
I know, as I've been on the other side of it more than once at work.

I think the 25 feet mantra is not really about staying an actual 25 feet from the track. 25 feet won't save you from rolling boxcar doors or the mythical ballistic pennies or forbid a real derailment.

I think it's because no one brought their tape measure to watch 4014.

I think it was more about trying to get people to stay 10-15 feet away. If you tell people to stay 10 feet from the track, you're lucky if they are 5 feet away. If you tell them 25 feet, maybe you will get them to that 10+ foot mark that probably doesn't terrify the crew too much.

Close to fifty years ago, I was taught the same principal of staying away from wire cable -- this being in my early days with a railway museum. Some of the mentoring members had had time with the military and/or rigging.

Now, chain is something else. It basically just falls in place. I have seen this happen.

Back to wire cable. I recall several reports of navy aircraft carrier restraining cables breaking and whipping across the flight deck severing portions of legs of the deck crew.

I helped a signal maintainer pry a penny out of an IJ, they don't belong on the tracks

My wife an I were on the northbound Amtrak that left at 1:15pm to LA. Departed SAN DIEGO on time only to slow before OLD TOWN. Stopped for over 30 minutes, only to return to SAN, detrain an wait for instructions. Thirty to forty minutes later we boarded same train along with the 3pm passengers to LA. Was a very crowded train by time we reached LA. I was tempted to detrain at Fullerton, to eat next to the depot. We were to catch Amtrak #4? east bound to Chicago. I requested a redcap to pick us up, due to luggage an I walk with a cane. A very nice Amtrak lady ticket taker took care of us thru all of this. We were taken to the lobby, obtained our car & seat number. Returned to the Chicago Amtrak train an were granted permission to board early. Our Amtrak train started to roll exactly at 6pm, only to stop 30 feet later for over 40 minutes. Counted as a on-time start I would say. OH, BTW the man in OLD TOWN died.