I don't think it's a problem to put a confirm of sorts in, but after quickly skimming through the WoWWiki on the quest events and API functions, I don't think the game flags escort quests differently, it seems they're just handled differently by some script that isn't visible.
If you could compile a full list of all the escort quests, then it would be possible to make a mod that on the dialog before accepting, it would inform you that this quest is indeed an escort quest. At least I think so, in theory, on a sleepy Sunday morning.
