Sometimes Rolling Flame is not reflected at a wall or object but goes through it.
In my recent case that was not only weired thing which happend:
Rolling Flame went through the closed door north to me where it hit enemies. It got reflected, but not only one Rolling Flame came back but two.
At the same time enemies south to me got magically hit by another invisible rolling flame. It's magic!
Please compare screenshot and savegame.
P.S. it's not the only bug related to this very particular spell, there are two other bugs too: one and another one.