When I went through Edison rage last fall my PMI said that many of the coaches and other PMIs had funny ideas, that they weren't always actually experts in what they were doing, but had just managed to get though the instructor and coaching courses within acceptable tolerances.
And for DIs lightening up, they were a lot lighter than I had expected, and many times hoped as I saw other recruits slip past. All I ever managed to get was a bruise on my arm from a 'helpful repositioning' while practicing drill once. Sadly they're taking more from us. By the third month of recruit training it came down from some higher ups that we were no longer permitted to shout a healthy 'Kill!' for motivation. 'Drill, drill, drill them all' just didn't cut it.