If the staff count fewer people in a room at the time of the murder than claim to be there, who is lying?

Question

Accepted Answer

The murderer. Staff never lie and innocent guests report who was with them, so the false claim belongs to the murderer, who claimed to be in that room at the time of the murder.

Awkward Guests: The Walton Case

If the staff count fewer people in a room at the time of the murder than claim to be there, who is lying?