Has he spoken to you about it? Literally spoken to you or has the only communication been via email? I couldn't imagine NOT speaking to my professor about an exam. There is no way that I would ever send an email requesting to take it on another day then MISS the exam without confirmation! That is what gets me here is that he didn't even know if you accepted what he sent and yet still did NOT show up for the exam. Seems to me like he truly just didn't care. I mean, how could you truly care and yet still not know if you were going to be able to take the exam another day??