I don't believe that he's portraying the mistake as TELLING her - she's rightfully pissed off that he'd been hiding something for so long. It's understandable why he did, because that's not something he wants to get out, but seriously, you seem to be overreacting to the reveal. You can find plenty of examples of women keeping secrets and it not being bad, and men keeping secrets and it blowing up in his work - there's no trend there.