Most of know that alcohol takes a period of time to pass through the body, and any atco who is not aware of the very stringent regulations which recently came into force, must be living on Mars.
It is very obvious that if you have more than 4 units of alcohol the night before, and don't allow 12 hours + before working, there is a high risk that you'll exceed the prescribed legal limits.
The atco concerned could have decided to phone in sick, equally, they could have, at any time after the alleged incident was flagged to management, gone home sick, and the only person who could have done anything about it, would have been a uniformed police officer.
Equally, once home, the atco could have taken a "medicinal toddy", which would have further confused the issue.
I am by no means defending the right to break the new legislation (which I support fully), but I do think someone has handled this very badly, mostly because the gutter press is going to have a field day in slagging off our profession.