Out of interest, if the headlights of a car were left on for an hour with the engine off could it ruin a perfectly good battery?

The car in question was a 1.7 Puma.

After the above incident the car refused to start wih jump leads. We were told the battery was kaput and would need replacing.

There had been many other things wrong with the car, which we had only got in November, and in the end we sold it, but I wondered if the battery was another dud thing on it?!