This is more of a "haha, look at what happened" post than one asking for help (as I'm not far in and don't mind restarting).

After going down a mine elevator and resolving a certain eight-legged issue, I grabbed what there was to grab and tried to head back up.

Only, as the screenshot (resized for upload limit) shows, the issue isn't completely gone. I can press the button and the elevator begins whirring, yet it won't move, thanks to the lovely spider :)

Is there anything I can do about this? Has this happened to anyone else before?

seems like a physics issue, such things can happen, though they are rare. make sure you are not forcing v-sync off, that can cause such problems. as for a fix, you will probably either have to load an earlier save (before the spider has died at such an unfortunate location), or restart the level.

It was most likely a physics problem, yeah :) V-sync isn't forced off. I restarted the level as it was about a minute or two in and didn't take long to kill the spider in a better location.

When I got stuck that way, I at least had the entertainment of killing the spider while it was stuck under the metal lift. But it's rare, and a flaw with the physics. A dead spider corpse can stop the working elevator/lift.