Commentary

A play showing the scholar escaping into prima custodia from binding below, and the priest punishing him by using the play of binder and the bound.

This is possibly the scholar attempting to escape away, not to perform a technique that involves leaving the bind. Otherwise I don't see why he would switch into prima custodia. In this case, "following" (based on the play of binder and the bound) would mean stepping forward, maintaining the distance and thrusting the fleeing opponent. Which is what we see in the play.