I hear what you are saying but for me if a guy I have not started dating yet pulls this mess what really does he have to explain? What he did and how he treated her is not the way to establish anything solid. I guess if it makes you feel better you can allow for an expansion but I wouldn't move forward beyond that. Realistically though his explanation would be bs. He effed up his one chance to make a good impression which shows he's just not into her so why bother wasting time?
Besides actions speak louder than words. A man will make time for what he wants. It he had drama, he should have respected her and her time enough to contact her immediatley to cancel.