or what you can do is the "slippery fish" trick thats on SCNPunk...basically, you make:
Trigger 0: Set as Objective: no, Looping: Yes, Starting State: depends on the scenario, if you want you cutscene at the beginning, put it "on"
Condition 0: Object Selected: Player 1, Set Object: your guy that you want standing still
Effect 0: Change Ownership: Source Player: Player 1, Target Player: Player 2 (or whatever), Set Object: your guy that you want standing still
Effect 1: Change Ownership: Source Player: Player 2 (or whatever), Target Player: Player 1, Set Object: your guy that you want standing still
then, when the cutscene is over, put another trigger to deactivate this trigger...
this trigger will let the player move a tiny bit, but its hard to move it, so most people would kind of realize that ITS NOT SUPPOSED TO MOVE!!!