What does he mean by,,,,

No doubt a reference to another femme fatale he encountered earlier in the movie, Harriet Bird (Barbara Hershey), which led to negative consequences for him then.

The setup was when they first met in the elevator at the hotel. Pops asked if they knew each other, and they both replied "no", they'd never met. Pops introduced Memo as his niece, and Hobbs as a new player.

Fast forward to the scene in question. Hobbs was again caught off guard by a woman with a gun when Memo fires the gun into the floor startling him. Hobbs, recalling how Harriet shot him as a kid, and lamenting to Iris that he should have seen it coming, sees Memo as the same type of woman as Harriet.

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