Had to see the last part of it again to figure out what Gus was getting at when he questioned Kim.
He asked her why Salamanca sent her.........and she told him Jimmy talked him into doing it.
Gus then had an epiphany that...........if Jimmy could talk him into doing something............then he could probably do the same thing.
Don't know how he knew Lalo was gonna be at the laundry spot.........but that's the only reason why I think him questioning Kim was pivotal to saving his life.
Well, maybe not saving his life, but ultimately killing Lalo.
Because if he had just stayed in the house like Mike told him to, he still wouldn't have been killed............but Lalo would still be on the loose.