I had that happen with a book I had recommended about 1.5 years ago. I suspect that they had turned down my recommendation and because I had chosen to be put on the waiting list if they bought the book it added it to my holds for some reason. Maybe in the vetting process they had put it on the "get" list and then changed their mind or something.
Whatever they did there was apparently a bug in the system. I went back and forth with them a little and ended up just cancelling the hold. They still haven't gotten that book though.
Have also seen it on new releases too. Calamity by Brandon Sanderson just got added to my holds list and it doesn't get released until next Tuesday.