Walt appears, unarmed and smug, like a substitute teacher who thinks he’s cool. He tries to motivate Mike the way he motivates lab assistants—by lecturing about “pride” and “legacy.” Mike, being Mike, just stares at him like he’s smelling week-old trash.
Then comes the line that seals Mike’s fate: “We had a good thing, you stupid son of a bitch!” He calls out Walt for his fragile pride, basically saying, “You ruined everything because your seventh-grade crush on your own intelligence trumps all logic.” Walt’s face goes through twenty shades of red.
