Whenever alleged "found footage" begins a few seconds before the amazing, once-in-a-lifetime occurrence or the blink-and-you-miss-it weirdness, you should be suspicious.
It usually looks like several seconds of why-would-you-film-this banality until someone suddenly says "OMG LOOK AT THAT!" and the camera swivels around to see the monster/alien/cryptid/magic for a second. Real footage of such unusual events would begin several seconds after the exclamation, at best, and that's if someone whips out their phone immediately. Also, anything that zooms in was probably not filmed on a phone.
Mokalus of Borg
PS - I'm not actually that familiar with high-end phone cameras.
PPS - They might zoom. But I doubt anyone thinks of that in the moment.