I think that the key is to make it safe to make mistakes...this also makes it safe to point them out...

This may be sematics, but in my experience, the bona fide assholes don't point out mistakes because they care about helping the person who made the mistake to improve. And so when an asshole sees they've made a person suffer, they don't care, and don't take the time to reassure the person that they have confidence in their abilities. When a person is being radically candid and they see the person is suffering, they take the time to show they care and to reassure that person they have confidence in their abilities--but it a way that makes it clear the mistake was a mistake, or that their work isn't good enough...