I found a new glitch that would make it "possible" to pass this level with a solution other than the intended one. I'm going to try it, but I don't predict success.
EDIT: False alarm. It wouldn't be possible and it's not a glitch.
EDIT2: While I was trying stuff I somehow made a lemming "slide" up through some terrain, as in a consistent upward motion at about the speed of a faller. This is the glitch that leviathan saw at some point. I have some idea of how it happened, so I will now try to reproduce it.