Still want to know how Gus knew not to get back into his car at the hospital parking lot.
Jesse saying, "He was poisoned," in reference to Brock got Gus thinking, and he probably knew something wasn't right. Of course, we didn't know that at the time, since the original assumption was that Gus did it, and the reveal that Walt did it didn't come till the end of the next episode, but still, I think Gus' just starting thinking about it like crazy and he knew something was amiss. The fact that Jesse had to then be knocked out, taken to the lab to cook, watched by a guy with a gun, and handcuffed whenever the guy had to step away (like when he was handcuffed when the guy went and got shot by Walt), just showed that Gus suspected Jesse and Walt were up to something.