Recreating the glitch I noticed that it also happens in the level before the one I mentioned, but it is harder to reproduce, so here is the glitch (I provided pictures for convenience):
- Position yourself and your clone like this and make a copy with q on these platforms
- Move to the red button, letting your clone fall to their doom
- Swap places with the copy. The copy of the clone gets violently dragged downwards thru the platform.
I don't actually think this would be a viable solution anyway, but getting snapped to hell isn't exactly what should have happened. (If I had to guess you probably parented them wierdly)