It feels like from what I’ve read it kinda went like thid
Harbaugh thought he was safe, and was mostly right, but shouldn’t have approached it that way. Steve, being who he is and how he got there, felt like it demonstrated he was out of touch and confirmed a feeling he had that Harbaugh lost the team despite them showing signs of life towards the end. Harbaugh sticking with his coaches despite it being obvious that a change needed to be made likely compounded things and confirmed to Steve he has to replace Harbaugh even if he didn’t want to do it.
In the end Harbaugh’s hubris got him.
I’m not sure if Steve spoke to players but I do wonder if he did. It almost feels like he knew there was a disconnect, although I have no doubt he could figure that out without speaking to them