I have a reason to think it's less likely that the scum's target has been protected from the scum. My guess is that the scum has been role-blocked by someone.
Well, it's a miracle since not only the scum action has been failed, but also the Serial Killer's, and I've just noticed it was a full moon night, that means other town-killing roles such as the werewolf should've been active last night too - if my memory about the full-moon night is intact, but i perhaps i need to ask the host about it -
I'm sure there is some information to be shared this day, without backfiring at the town.