Level 6 glitch/stuck [spoilers]

[Crankcase]

level 6 (into the fire) where you go to hell:
halfway through the level there is huge door to pass through - this is after getting yellow and then blue keys and passing through the blue key tunnel to an area with 2 cacodaemons...
I hit the skull button to open the door, go through, fight another set battle, then discover I've likely forgotten a secret, so I jump down a cliff back to the other side of the door - get the secret (it was a rune quest), then go back to the door - now it's shut again and the button is already pushed...

is this a reload the level situation?

[Bill of Rights]

Found a video when I was researching this same problem: https://www.youtube.com/watch?v=5TJzMqLni1o