Hi, I had exactly this problem and got round it by resetting four of the dials BEFORE going through the newly opened door. In other words, I set the dials to open the door, turned four of the five of them back to the start position and went through the open door. After being chased back to the dial room there was plenty of time to reset the last dial, the henchman didn't appear in the doorway and the game didn't freeze any more. Hope it works for you.
The universe is full of magical things, patiently waiting for our wits to grow sharper.