I just watched it, so incredible. I also considered for a second how realistic it was for Gus to survive for that long but it quickly didn't matter due to how incredibly evocative that reveal was. That tie adjustment mannerism was fucking ingrained in him.
Huell was very specific about patting Jesse's jean's pockets. I think the easiest way for him to lift the ricin would be for him to take the whole pack and replace it with another. My question at this point is how complicit Saul was in the plan and I'm guessing... not very? I dunno.
Let's not forget how awesome Hector's death was. His eyes were all like "aww wait don't kill me, Gus-- YOU DIE!"