When a person is killed, the bladder releases its contents. If she was killed in DW's house, something should have been soaked with it. He washed his bed linens, but his mattress was apparently dry.
Again, there should have been a lot of urine somewhere, no matter which scenario you choose.
So. Where is it? Not at DW's house. Not in his motorhome. Maybe in Danielle's bedroom, but they're blaming that on Layla. Dollars to donuts the carpet wasn't tested.
Ding, ding, ding! I think we have a winner. All that Layla testimony didn't make sense to me. Now I see. Layla provides a smokescreen for perhaps a lot of damning evidence. It seemed so silly to spend time at a murder trial talking about a poorly housebroken dog (guess BVD didn't have time for her, either), but not if that dog becomes a convenient patsy for a coverup.
Makes the mysterious dog bed that much more important, too.
Thanks for all the solid thinking you've put into this.