Luka is arguably the best pick and roll user in the league. One thing he is really good at is using his pace and understanding how defenses are playing him.
In this film you will see how he takes advantage of when guards go over top his screens and keeps them on his hip/back. He knows that defenders are taught to try and get back in front as soon as possible, so he will use their momentum going forward and will create separation by using his step back.