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e f g 1 h Why it works
3...Qg5 already flirted with disaster, but the losing moment is 4...Qxg2?? — the most famous poisoned pawn in the open games. White has a forced sequence: 5.Bxf7+! decoys the king (declining doesn't help, the bishop just leaves), 6.Rg1! hits the queen with tempo, and after 6...Qh3 comes 7.Ng5+! — a family fork the queen walked into: check on the king and an attack on h3 at once. 8.Nxh3 banks the material. Grabbing g2 against an unmoved rook on h1 hands White the g-file for free.
Refutation
4...Qg6 keeps the queen near the action and out of the cage — g2 remains taboo but Black's position holds together (engine −1.1, the price of the early queen tour rather than of any single move). The takeaway works in both colours: a rook still on its home square makes its knight's-file pawn poisonous.