I got a book back recently with glue all over the place between layers. Got a free re-holder and after 2 months it came back with a curly shard of plastic on the front. Just sent it back for another free re-holder. My OCD can not handle that and it should have been caught by QC as it was huge and in the front and I dont want it pressing into the book. I never had a problem with a book before (besides the oil slicks that aren't worth doing anything about), but twice with this one.
If it bothers you at all, send it back....their mistake that should have been caught.
If it is a sharp or solid item, definatly send it back so it doesn't ruin your book!