Wow! That's not how I expected the story to end at all. I'm very sorry that happened, and I do agree that he should have been more transparent. I have no idea how I would handle this situation, but I imagine I would feel like you, pay the bill, and be very wary of him next time. I suppose you would have legal grounds to oppose paying, but that would probably end up costing more than the original bill and you'd probably lose a friend; although at this point, I'm not sure he's much of a friend anyway. I hope he is more upfront with his customers.