To anyone more familiar with the law: is this the type of thing that could be recovered later?

I think the lawyer was smart enough to ask for an amount that he'd be okay with, but kept it small enough to make paying it easy enough to not warrant the startup being distracted.

But say the amount was more and the amount was low enough to pay the guy off, but high enough to be concerned about. Maybe you still pay it right away because you have to in order to get your funding, but is there any case law that supports recovering this money later on because the startup was essentially held hostage by the lawyer?

It seems fairly reasonable that a contract made under duress could not be enforced, or could at least be brought up at a later date.