Don't send him your coins. You are not his insurance against software bugs. We are grateful that you help develop bitcoin and that must be enough for the guy who lost his coins.
That said, I feel bad that he lost a couple coins due to a poor coding mistake.
I'm not sending him the full amount (largely because I dont have much left myself) but still, I fucked up, and, if nothing else, should pay him in appreciation of his willingness to test my code.
In any case, this is a good opportunity to reiterate the standard "this is code written once and only mostly tested, it has not been looked over by others, and not even much by me since I wrote it, it is beta and should not be expected to work 100%"