I still don't get it ..... Saul took the ricin cigarette from Jesse then all of the sudden, Jesse was out of control rage and attempted to burn White home (myself turning point plot). What's the purpose anyway?
Hopefully I'm remembering this right.
Before Brock got sick, Walt had Saul (who in turn had Huell) take the cigarette off Jesse so that Jesse would think Brock was poisoned by the cigarette. At some point Jesse remembers that Huell had tried to physically stop him from entering Saul's office and he's convinced that Huell snuck the cigarette from him and that it was all a big plot by Walt (which it actually was). But then Walt convinced Jesse that it was Gus who had Brock poisoned. (It was Walt who poisoned Brock with Lily of the Valley). Then in the next episode, Walt plants a new ricin cigarette in Jesse's vacuum cleaner and they find it.
Fast forward to the episode you're talking about, Huell takes weed from Jesse's pocket. Now Jesse is reminded of how he thought Huell took the cigarette from him. He's now convinced that he was right all along and it was all Walt's doing. Which means he's convinced that Walt poisoned Brock and totally manipulated Jesse.