Stupid Things Seen in the Gym

I hate using the word stupid, but I have no other word to use. Being in the gym every day, either on my own or with a client, I always have an eye on people. I watch how a person performs an exercise. I watch what other trainers are doing with their clients. If I've been watching someone for awhile, I'll try to break down their workouts. I'll even try to listen in on conversations (yeah, I'm nosey). Something usually stands out everyday, and usually it's not a good thing. In fact, this could probably be a daily column. But, I do not want to insult. What I am trying to do is correct people and understand their methods. If they give a justifiable reason, I may understand. If they recite studies from Maxim or Glamour, I may have a problem. Enough rambling.
This is one of the more bizarre things I've seen (and that's leaving out what goes on in the men's locker room). A guy, probably in his fifties, was standing on the rounded side of a half foam roller (the bottom side is flat). He is in a split stance, one foot in front of the other. From this position, he was attempting to jump on the rounded side of the BOSU ball without falling. Immediately, as soon as I start watching him, he stops his set and leaves the area. Now unless this guy was training for a lumberjack log-roll contest, I have no idea what his purpose was. Here is another situation of someone probably not being able to perform a basic lower body exercise, such as a squat or lunge, and just trying to over complicate things. If I had been able to ask him what he was trying to do, he probably would have told me, "Working on my balance". That's when I would have told him to work on single leg exercises (step-ups, lunges, single-leg squats). It's not about training the very specific aspect of balance, because only those aspects are going to get better. In order to have better overrall balance, work on the muscles that are involved in order to keep you upright (glute medius, peroneals, hip abductors and adductors).
Always think an exercise through. And if it seems foolish or requires more than one unstable training device, kick that exercise to the curb.