I can understand the ref not giving it when he probably thought was that inside the box, was it a foul. All I saw in real-time was KDB getting sandwiched. It was a tough call. I think video showed a foul on the line but the VAR probably thought it was not enough to overrule the ref.
I hate these VAR grey areas. These are where the Man Utd and Liverpools get the calls and for the rest of football it''s a lottery. I would rather they get rid of VAR and put all the trust in the on field ref. I think if he had to make the call on his own, he might have given the pen because he would have been forced to make the absolute and final decision in the moment. VAR is an excuse not to make decisions.