I play this hand at " Just Play Bridge (Free)".
I should say my 5♦ is not good,but fortunately the accident happened,GIB discard ♠K angrily,ha-ha,very interesting.
My best guess is that GIB simulates you always make +2 based on the HCP you showed. I'm not a good enough player to tell you how, though.
If you hold singleton ♣K and ♠Qxx to go with your ♥KQ you still have a loser, so presumably you could always squeeze your way out of it?