I don't think it's common nowadays because probably people are more careful and there are often warnings if the fee is set too high, but at least with high fees I remember people even getting a lot of their money back from transactions mined by P2Pool, as unlikely as that sounds.
no, I think that was slush's pool that returned the accidental 100 BTC transaction fee (the original thread was here on Bitcointalk, cannot remember when though). P2pool would've been a nightmare to get overpaid fees refunded, there were usually 100-200 payouts per block, where the 50 or 25 BTC reward (don't think p2pool survived past 12.5 BTC) got paid to that many addresses. They'd all have to have been paying attention (and be sympathetic to the mistake too) to refund it all! Slush's pool is still pretty big last I checked.