Yeah sounds like a way to get hurt.
Thats a very, very good way to get hurt--not just the pectoral tendons, but also by falling off the bench or dropping the dumbells. That trainer should not be allowed to train anymore. He's obviously stupid.
I wish trainers like that would make the mistake of getting a female cleint who really knows what she's doing and then she'd rip him a new asshole the size of Texas for being an idiot. And then if he insisted, fall off the bench and threaten a lawsuit for her injuries.
What I want to know is what dumbass taught this dumbass that? And why only women?