I think that he was just disappointed after realizing obito was the masked man in the flashback he wanted obito to become hokage. now I guess he realized obito joined the darkside
Minato was sad. Just think about it. Your student who you trained and cared for turns to the dark side. Minato tried to teach him to be a good shinobi but Obito was still turned by Madara. I'm sure anyone would be sad and feel like a failure after that
No I don't think so, I think he found it just sad what Obito has become ... or maybe he did ... Obito is responsible for his and Kushinas death afterall. ...