Sorry to hear about your troubles.

I am wondering if you could elaborate on the "detainment" part by this awful FA.
How did that actually happen?

Did he say: "Stay in your seats until everyone has deplaned and then you will be arrested."
Did he restrain you physically?
Surely some other passengers would have heard & seen this and questioned it, or sympathized with you in some sort of way? Or maybe other flight attendants: surprised that other FAs didn't notice this and get involved either by agreeing or disagreeing with this bad FA. FAs tend to know what their co-workers are up to, and I find it hard to believe he could do all this bad behavior without any other FA noticing.
As a veteran I am surprised your husband was this compliant with this odd behavior and demand of the FA.

What a dreadful experience!