The spidey sense scene I was talking about was when Gus enters the hospital parking lot and "knows" something is wrong with his car.
I agree that it seemed weird at first, but given the fact that it was actually Walt that poisoned Brock, not Gus, Jesse's behavior would have seemed very odd. Given Gus's extremely careful nature of always being ten steps ahead, it's not hard to imagine that he would be very suspicious after essentially being lured into a public place by some random event that he knew nothing about. He also must have sensed Jesse's anger towards him given his own history of allowing children to be put into violent situations.