Would have to put focus on that single useless spotter from his position of behind the gentleman squatting.. . He was part of the problem, for he tend to get in the way of what may have been a possible better exit path for the squatter when the exercise started to go bad. Now hind sight of course, the squatter is dead.
Having two spotters, one on each side, would have been a safer method, if having any spotters at all. Though the gentleman squatting appeared crushed by that weight in that extreme low position, spotters or not. (?can't tell by the video if there might have been spotter on each side?)
Could say the same for heavier benches and the uselessness of one guy spotting from the rear....madness of course.