They should have had some sort of warning or disciplianary action. My brother (working part time) was fired from the high street stationary/books retail store because he didn't make it into work because of the night before.
The thing is he could've gotten away with it as they phoned him up asking was it due to alcohol, and he said yes. However he couldn't have been thinking straight, if at all, as he was in a&e a couple of hours prior the phone call xD
Why should they get any kind of disciplinary if the company is happy to let them off with it? it's upto a company to decide if they want to be strict about abscence