(More a documentation of that this is a thing)
In the Section with the Platforms moving around some boxes, Staying on the last set of boxes as they go into through the Doorway, I got teleported far to the right, were I was basically just before the Climb for to the Level End Cutscene. Still inside a Wall, but I was able to clip out by going up.
Only thing strange I noticed about the time this happened was that there was a 2nd Platform, but without the boxes flying on that path just ahead of the one with boxes.
I sadly wasn't recording at that time, just practicing some Levels in general.
Trying to reproduce it, generally either has me clip up on top or hit a Warp back to in front of the door.
I stood on the boxes like I did in this Image: https://1drv.ms/u/s!Auurp6qqdF68jfdL9EYfqt7UFOPkNg?e=EZ2EBY
I'd be interested in trying to reproduce this glitch for youtube documentation as the link here has expired.