.
I think he does lie, but being BM, he could have hired someone outside Salida to help him, some totally unsavory type. BM hunts, he hires different people to work for him, he sells antlers, he can come across someone who is not linked to him and can murder for hire. Only, unlike KK the clean-after-murder nurse, the person did not take the cellphone as incriminating info with him.
Then BM could have been, indeed, in Broomfield, when it was happening.
That could explain $70 K missing. This is a good payment for some criminal, who, too, disappears, because least of all he wants to be tied up to the case.