I've always assumed he was away a long time, and assumed that by the time he came back a maintenance crew would have got round to fixing things. I suspect vandals often make that kind of assumption.

Incidentally mention of vandals ties into your comment about Ralph not being a plausible name for a villain. At the same time the historical Vandals were rampaging around after the fall of the Roman Empire there was another mob in the same line of business - the Alans. But somehow, unlike the Vandals the name never caught on in later years... Some names work for villains, some don't.