I often want to say no. I often want to go and help, but these days the most I will allow myself is a visible grimmace. If they catch it and want to ask id be happy to help though. Most recently I saw the ugliest squat form, with knees just caving heavily and all the weight rolling in on the ankles. These were clearly warmup reps too and all I could think was that this guy is going to snap something as soon as he loads the bar. At the end of the day its just not my place to say.