The fact that the employee got the sack kinda proves that the sentiment was correct; it wouldn't have resulted in a disciplinary if the manager hadn't complained, I'm guessing. There are times when the best course of action is to be self-reflective - this was probably one of those times...
You're kin kidding me, shirley?
I got the sack as a 20-something for "....working too hard, you're upsetting your colleagues who feel that you're putting them to shame. I need to keep them happy, so I'm going to have to let you go". I thought he was kidding. He wasn't. The company went bust...