Title? I don't need no stinkin' title.
In 5e, that's not even a switch or an override, it's just making different rulings. The villain tries to escape, the DM narrates successful escape, the players try to stop him, the DM narrates failure, the party tries to track or pursue him, the DM narrates the pursuit taking them to a side-encounter or dead end.
Perfectly orthodox 5e play dynamic.
I hate it when video games do they do that. Even worse if it happens during a D&D game. YMMV of course, different people play for different reasons.