Dumbledore seems quiet desperate to find a Defense professor, so much he’ll accept about anyone (except Snape, but I guess that’s because he wants to keep Snape in Hogwarts for more than one year), both in canon and in MoR. He keeps a close eye on the defense professor then (or at least, he does in MoR, he didn’t seem to do it much in canon).
Dumbledore seems quiet desperate to find a Defense professor, so much he’ll accept about anyone (except Snape, but I guess that’s because he wants to keep Snape in Hogwarts for more than one year), both in canon and in MoR. He keeps a close eye on the defense professor then (or at least, he does in MoR, he didn’t seem to do it much in canon).