Personally knowing one incident, extremely thoroughly.
It's taken several years for it to be resolved, with increments made only after rigorous checking and cross checking.
I'm certain that the chap is not overclaiming, but has to fight dogged resistance to any offer even approaching "fair".
I can't answer for others, but the one I do know about the RAF/MOD haven't paid a penny more than they have been made to pay.
It was a low flying incident that scared a large flock, causing deaths and loss of egg production and you can't simply restart a flock overnight.
It was no one's fault, absolutely not his and the pilots didn't overfly deliberately to scare the birds but the MoD still were rigorous in ensuring that no one more penny of taxpayers money was wasted. Unfortunately, the case meant 2 years lost production, and hard to rebuild his business.