If you admit that "you should have pushed back asking for more details" than you should also admit that because of that, you are partly liable for the fact that he did go beyond the explicit rules. Now, are those rules also in Arabic? Also, how are you to encourage users to work with you in a quick, efficient manner, if these kinds of things are bogged down with red tape? It's only $500. Perhaps, you should change your rules to make the system for bug reporting easier, efficient, and a bit more egalitarian. Best,
LJ