Morning Rainboe
For me the difference would be that IF the reason for the divert was a disruptive CC, he still has to conduct a safe approach to the divert airport, when he could have carried on and also conducted a safe approach to his original destination.
Get the SFO to interact with the CC for the rest of the flight, if she is such a pain in the backside and then do any disciplinary proceedings on the ground at the original destination.
I understand that distractions can be a factor in incidents and accidents, however if UA come down in the favour of the captain in this one, they may be setting a dangerous (costly) precedent.