I lean towards hoax, but who knows. Seems like those hot dogs were made pretty photogenic, you want to really do something scummy like this do this you put the slivers all the way in, right? Not sticking out of neatly cut segments so someone can see them or the dog can feel them in their mouth.
Freegards
Now that you put it that way, you could very well be right with that passe-partout. There could be some sort of a vendetta going on.