Then he gave you the wrong kind of night guard.
Sometimes I find it hard to believe I practice in the same profession as some of the yoyo’s who call themselves dentists.
Do I ever screw up? Certainly, every human being does. But I would never put it on the patient and I would make sure to let them know I screwed up and I’ll pay to fix it.
It’s stories like you and @ClaudnDaye tell that really make me angry at some dentists.