@RH88 With all the descriptions you provided, it seems the supervisor is an abusive person who does not care about the students. No matter you (or other lab members) decided to leave or not, please do a favor to future postdocs (and also to yourself) and report this to a higher authority (e.g. department chief, labs director) in the university/institution which the lab is part of. The supervisor needs to be understood or reminded that he/she cannot break the code of conducts and the contracts you have with him/her.