Disclaimer: I’ve only played offline dynasty.
Which bowl week did you lose your DC? You should’ve had multiple weeks to find a new one (unless you lost him in bowl week 4).
Your commish didn’t advance thru multiple weeks did he? If so, then he skipped a week when you could’ve tried to hire someone else after your 1st guy turned you down.
Are you sure the guy you offered didn’t go elsewhere? You can find him in the screen where you can see everyone who was fired/hired/went pro/retired/etc. if he took a coordinator job he won’t be seen in the coaching stats screen.
When hiring a new guy, I always check his other offers (think it’s at the bottom of his “card” when you’re looking at him). If he has better offers or ones that might be better (any HC job or coordinator job at a more prestigious school) then I’ll likely target someone else. I wanna make sure that I get a decent guy and not offer someone that’s just gonna say “thanx but no thanx. This offer is better than yours.”
His scheme doesn’t matter outside of role playing.
You can fire him during CCG week and only during that week.