The question is did Walt Calculate out the exact amount of poison he could give, to where he would harm Brock without killing him, or did he just throw a random amount in and hope for the best, accepting the possibility he could have killed Brock. Walter poisoned Brock in season 4 of Breaking Bad but the truth didn't come out until the following year. The character Brock Cantillo (Ian Posada) was the six-year-old son of Jesse Pinkman's girlfriend, Andrea (Emily Rios). Brock greatly admired Jesse and the two would often hang out and bond. After Jesse and Andrea broke up, he continued to.
to make jesse believe brock was poisoned by walt himself! it sounds weird, but walt needed a reason to get jesse to come talk to him. he had to work out how to kill gus, and at that stage jesse was estranged ( he didnt want to see walt ever again ). walt estimated that by enraging jesse (ie making him believe walt did it) jesse would come to his place and try to kill him.. Walt tricked Jesse into believing that Brock had taken the potent poison ricin. Walt, however, could assign Gus responsibility because he had previously harmed children.