The earliest note of an apology I can find was June 11th. It took Mike Milley 5 days to realize he'd been lied to about the purpose of him following Trump? I could see this being political where he was hoping it would blow over quickly & he wouldn't be dragged in, but only apologizing when it didn't. That's politicking though & I would hope that military generals, in an age of misinformation, are proactive about correcting the record. Another interpretation is that he was 100% on board with the President's plan & miscalculated the impact it would have on him.