Originally Posted by TonyR
But did he know that Huell lifted the ricin cigarette? Or did he suspect it? I know if I was missing something from my pocket I wouldn't immediately suspect that someone had picked me. And then if I did suspect it I don't know that I'd immediate suspect they'd done it with something else before. I know I'm over-analyzing this but it was one of very few times something didn't work for me on this show. But, I'm sure much of it is the details not being fresh in my mind.
He suspected Huell lifted the ricin cigarette. But he knew Huell lifted the joint, which suddenly brought a lot of weight to his earlier suspicions about the ricin. The whole ricin in the Roomba thing seemed flimsier in retrospect, especially given Walt was involved in discovering it.