In yesterday's session, our characters scouted a room full of reanimated corpses, and it was the only way to go through. Our characters were completely exhausted of resources and couldn't rest, so I decided to make good use of the only object that could give us hope, the Deck of Many Things, and made my character draw several cards. One of those was "The Fates". I used its effect to erase the reanimation of all those corpses in that room. The DM accepted and didn't misinterpret my erase of the event: all the corpses became inanimated.
Later came the time to reap the rewards, including the XP.
My DM gave us the XP for all the defeated mobs, except for those corpses in that room. I argued that in my view, there was an obstacle and I used a magical object to overcome it, so it took a resource from my part, and me spending a resource should be enough for our party to get the XP. There was no consensus among the other players either: three followed me, one backed the DM not on the "avoid the fight" problem, but on the fact that he's got the final word.
In the end, I accepted my DM's judgement, but didn't (and still don't) agree with it.
How is XP usually handled in such scenario when the players technically overcome an obstacle, by erasing events from the past?
Notes:
- My DM usually awards us with XP for handling situations in creative ways (meaning, no fight).
- We asked why we didn't get the XP, the DM said that in the end there was no monster to fight, no obstacle to overcome, so no XP. I trust his word because I've known him for a long time and when he's frustrated with something, he says it. He admitted being frustrated in this instance, but said that had nothing to do with the result.