How could Ardam have casted teleport? They were in a town (as Karn pointed out), teleport spells can only be cast on the world map, and only take you to the gates of other towns....
Oh wait, the bartender said the bar was on city limits... but still, how'd they end up in a TREE? Is there some sort of treetop town we haven't seen yet? shrug
Teleport spells can be cast in places other than on the world map. In many games they can be cast in battles, dungeons, etc. Plus, logic kills the joke.