In my opinion, and BM's defense...he did "act like a frantic husband looking everywhere for her and running through every possibility of where she might be"......just before he killed her.You seem to have missed the point about him being “in character.”
He did not at all act like a person who is wondering where their spouse is. If he truly had no idea what happened to her and that she was missing and he was panicked looking for her he would be going through all the possibilities of where she might be. BEFORE jumping straight to “she’s dead” which is what he did.
He knew she was having some type of affair so he might have speculated that one option is she had just snuck off with her lover for a bit, whether in person or on the phone. But he didn’t say that. Actually he lied and said that he knew nothing about an affair (because that happens to be motive for murder).
He knew she was recovering from cancer and serious cancer treatment so he might’ve speculated that she collapsed somewhere in the house or around the house. But he didn’t say that. He didn’t walk around or run around looking.
There’s many options that a truly innocent person would start with before they jump to the absolutely ridiculous, bizarre, and highly suspicious theory that a mountain lion ATE HIS WIFE!!!
Why is all that important? Because he was trying to ACT innocent, and in such a poor way that it was very obvious he was putting on an act. He did not at all look like a truly innocent husband frantically looking for his wife in the first hours that everyone was wondering where she was. Actually what he was saying and the way he was acting so passively was suspiciously implying that she is dead and gone forever.
In character, he forgot he is first supposed to act like a frantic husband looking everywhere for her and running through every possibility of where she might be. Instead he very ham handedly jumped straight to trying to explain alternative theories of why she was dead and gone forever. No one does that unless they know for a fact she’s dead and gone forever.
By the way can that be my submission for his book title? A Mountain Lion Ate My Wife!