Nawaz Sharif landed at Islambad, but was made to leave for Saudi Arabia
News reports suggest Nawaz Sharif went back to Pakistan without thinking too much about the details of the imminent confrontation (for example, when asked to hand over his passport, he and his colleagues did not have a pre-planned strategy to cope with the situation; the entourage was not prepared for how much pushing and shoving it was ready to take, and where to draw the line).
Most importantly, Nawaz Sharif picked up the wrong city to land in to. Not sure why he did not go straight to Lahore, his power base. In Lahore, it could very well be a completely different story. Imagine hundreds of thousands of NS supporters gathering in and around the airport; imagine PML-N local leaders preemptively threatening officials who would be found responsible for turning back NS, etc.
A suit for the contempt of court (in not letting NS in) has already been filed. Let's see what comes out of that.