I was dinkin' around in the Tutorial map, and after about fifteen minutes of play, any weapons or other pick-upables became un-pickupable. Like, I would direct a given body over it, and the action wheel menu was stuck with a greyed out "Reload" action in place of what should have been "Pick up X gun/item". Is this a bug or was I playing with a body that had crippled hands or something (which shouldn't have been the case since they were at 100% health)? The items themselves were apparently in good condition too, since they had their names and little arrows pointing to them hovering above.

{EDIT}
I should probably add some of my system environ stats:

Windows 7 x64 w/SP1
Microsoft Security Essentials
Malwarebytes' Anti-Malware Pro
Process Lasso (though I've made sure to exclude cortex command.exe from ProBalance restraint; For more info on the program itself, if you haven't heard of it, see this site)

I'm playing B24, without any mods.

Did you happen to order other actors, or maybe just a whole lotta crabs?
Because once there's more than 255 MOIDs (AKA movable spritestuff like devices, actor pieces, etc. that's not terrain, particle or glow) in the map, old ones are gonna turn to terrain. So the devices turning to terrain might be because you passed 255 MOIDs. This is the most plausible explanation.

No, I only ordered one body at a time, and I walked a couple off the edge of the map, and dug one through the bottom of it. You think it might be all those Drop Crate fragments?