i would not have him off leash again, because of 2 reasons 1. if a similar incident arises there could be horrible implications 2. the incident may have made him anxious and more likely to bite in defense again.
Exactly. Well put.
Alan, the problem you are facing is not whether you feel your dog is dangerous or not, but the decision of the authorities, who will most likely conclude that he is. Sad, but true, I'm sorry.