job denied coworker days off for his college graduation.

just found out at my retail job (forced to work 40 hours a week as a part timer with NO full time benefits) that my coworker requested the weekend off for his college graduation. the manager dramatically pulled him aside and lectured him on how he cannot do that. he gets frustrated and tells her he will quit if that’s the case. she then asks for proof that he’s actually graduating… this is so ridiculous