I had something similar happen with my copy of Dixit. Well, someone
wasn't being careful and sat on them. Two cards are now unusable. I
light heartedly gave them a hard time. It's a shame, but it happens
when you actually play your games. I'm not a big fan of sleeves,
especially with opaque backs. I like to see the art on both sides of
the cards.
Fortunately Resistance isn't too expensive.
Nate