Right when the season ended, I lost my QB coach. He was still under contract for 1 more year. I couldn't find anything in the transactions to show what happened to him. I don't understand what happened, can someone explain?

He could have retired, I am not sure if it shows retired coaches

You have to have your filter set to show retired coaches.

Never have had it happen so never noticed if it was there..lol

I see that he was hired by Dallas. I didn't want to lose him, so I don't understand how he just dropped from my team. He had 1 year left on his contract.

If someone offers your coach a better position then he can be taken. I haven't had it happen yet myself but thats what I read somewhere.

Because coaches can be hired on by other teams even if still under contract for a promotion.

Don't they have to get permission from his current team. I believe that's the protocol and the current team generally allows that coach to interview.

Its protocol in the NFL but it usually isnt standard as most teams dont deny the opportunity.

Here you have no choice in the matter. The coach wont leave your team for another position coaching spot besides moving to a HC, OC or DC position or at least he shouldnt. So another team cant offer your QB coach more money to take over as that teams QB coach.

Right, if he's still under contract he shouldn't be allowed to leave for a better position or for more money laterally. Should be treated as a trade, coach for player, coach for coach, coach for picks, coach for money.