Give the guy a break!
I'm sure most of us have turned up for a lesson after a night before having had a legal amount of booze...
Sunfish, this occurence was obviously unexpected and also a lesson learnt perhaps about the dehydration side of things.
For a sensible answer on your questions I would consult your AME.
There's far too many people on here ready to give you a b*ll*king without knowing the full story.