I've just finished episode 2 of Ghost Story and the whole issue of Morris being locked in the bathroom is weighing on me.
Is there any evidence that the bathroom door was broken down after he died? The podcast makes a big deal about it being a locked room mystery and guessing how Faether could have gotten out after locking the door. But the door was open before anyone else came to the scene, right? Because Faether had already broken the door down and inexplicably washed Morris's hands. Why doesn't anyone raise the possibility that Faether just broke the door down to kill Morris?
And think about which scenario is more likely to end up with a man locking himself in the bathroom. Scenario 1: you just witnessed your psycho brother in law shoot your sister, and now he's blocking the exit and is trying to kill you. The most obvious thing to do would be to lock yourself in the bathroom and arm yourself with whatever you can find in there (like a razor).
Scenario 2: you've just killed your sister and (you believe) your brother in law. Nobody else is alive in the house. You want to kill yourself. At this point, why would you lock the bathroom door? You wouldn't even shut the door to go to the toilet. Who is he locking out? He's not worried that someone will come in. If someone gets to him, they're more likely to kill him themselves than stop him. This scenario is just absurd.
And, while we're on the subject, if you're Faether, your psycho brother in law has just killed your wife and locked himself in the bathroom after you faked falling down the stairs. What do you do? Do you a) call the cops and tell them to come quick, the guy is still in the bathroom. He may have killed himself but I'm not going anywhere near that guy, he just tried to kill me. Or do you b) when you hear him lock himself in the bathroom do you run up the stairs and smash the door down so he can actually kill you if he's still alive?
It's far more likely that Morris locked himself in the bathroom to protect himself. Faether smashed the door down, managed to get the razor off him and use it to kill him. Washed hands so nobody would ask why they didn't have any gunshot residue, then called the police. No locked room mystery at all.