Just wondering... I had ~3 silver stolen by goblins (in about 15 seconds) and after I killed them, I got 30 coins returned. Yes, I killed all of the ones I was fighting, and no, no other goblins took the coins (lured away two goblin thieves, killed them both.)
Well same here, i guess they only give back 1 stack of money.
If the 250 are full and you get more coins, they will only give you the rest.
So if you have 3 silvers in 300 coppers, you get 50 back. Thats why you cannot powergame there for money xD