Should I have made an ''hellmuthian'' laydown here?

[Tharpab]

5 seat SNG and top 2 paid, 3 left I'm chip leader with 1900, SB has 1300, BB 900.
I got dealt K9s on the button and since I stole the blinds some rounds earlir, I raise 3xBB, they both called, flop cames KK4, SB and BB checks, I fire 350 on 900 pot, to make look like a bluff as I stole some pots, the BB min raises, SB folds, I call, turn is a rag, he goes all in, at the point it was pretty obvious he had it too, I think for a while and can, KQ, I'm left crippled, is this a laydown situation?I'm starting to believe it is, he probably woundlt have called PF with K8, so it was pretty stupid calling, laydown?