Depends largely on what you're comparing it to, but doing it in public is pretty grim. It's not the devil's work by any means, but shows crap judgement and booze is not a defence.
He's young and should be forgiven his minor indiscretions. But they're not irrelevant, mostly because they will be held against him should he not have learned his lessons, if not by us then by others.
Hartley Hare is also right that it wouldn't be hard for a player to show that he's done a bit of research about the club he's joining. But I'd not single Carruthers out for that, as he's one of hundreds trotting out the bland footballer speak we have to endure as fans.