You didn't indicate whether "in the round pen" was saddled or bare, loungeing or riding, or just loose. Makes a big difference to me.
If he's loose, I love to watch them kick up and expend some energy. If he's loungeing bareback, I don't mind a little, but when I start giving commands, I expect it to stop. If he's saddled, I don't want any screwing around. If I'm in the saddle, he's going to "get a good talking-to", as my dad used to say. Translation: he's going to wish he hadn't done that.
I would hesitate to criticize the trainer unless I knew more about what was going on.