I definitely believe that Saul knew Walt poisoned Brock. Throughout the series, Saul is portrayed as a shrewd and cunning lawyer who is deeply involved in Walt’s criminal activities. He is Walt’s go-to guy for any legal advice or assistance, and he becomes an integral part of Walt’s operation.
In the fifth season premiere, “Live Free Or Die,” Saul confronts Walt about his involvement in poisoning Brock, the young son of Jesse’s girlfriend, Andrea. Saul clearly expresses his displeasure, stating that he didn’t know the kid was going to end up in the hospital. This statement makes it abundantly clear that Saul was aware of the poison and its intended target.
Saul’s reaction to the poisoning incident is telling. He is not only concerned about the ethical implications, but he also realizes the potential legal consequences if the truth were to come out. Saul is a lawyer, after all, and he understands the gravity of such a crime.
Furthermore, Saul’s decision to sever ties with Walt in that same episode supports the notion that he knew about the poisoning. He recognizes that being associated with someone who would stoop to poisoning a child could be detrimental to his own reputation and legal career. Saul is always looking out for his own well-being and knows when it’s time to cut his losses.
Additionally, during their conversation in “Live Free Or Die,” Saul mentions that he is no longer willing to be Walt’s “hatchet man.” This implies that he has been involved in some unsavory activities on Walt’s behalf in the past, potentially including the poisoning of Brock. Saul’s desire to distance himself from Walt’s actions further suggests that he was aware of the poison incident.
Based on Saul’s reaction and statements in “Live Free Or Die,” it is clear that he knew Walt poisoned Brock. His knowledge of the incident, his concern about the consequences, and his decision to end his business relationship with Walt all point to his awareness of the poisoning. Saul understands the severity of the situation and wants to protect himself from any potential fallout.