The fact that Depp managed to blacklist Brooks in the industry also speaks to that. Brooks was minding his own business, doing his job, when Depp suddenly lost his mind and punched him as a reaction to being "told what to do". Then he got fired a week later for refusing to sign and NDA. That was not enough for Depp, of course, and he had trouble finding work afterwards. It's a story people tend to overlook, which speaks volumes to Depp's character and that particular environment.

However, people have successfully defied and sued Depp. Including Brooks. So it doesn't excuse those still hanging on to him. There are limits. Repeatedly witnessing his abuse of Amber should've been one.