I think, without seeing it, that paper vs. plastic will be okay, but as always, if anything seems off, call the vet.
I have had dogs eat cupcake paper - sigh - and others, and it was okay. My go-to when someone eats something, is to give them a piece of white bread or 2, depending on the size of the dog. Unless, of course, it was toxic, sharp, etc.
Please let us know how he's doing. I'm sorry that I'm so late. Lots going on here, too.
Love All Life, Thank You For Posting! :)