I'm not exactly sure, I was on Desktop for a significant time while the game was running.
However, the remaining caltrops where still around, as where the loot packets, I don't know if I could have looted the same stuff again. I've seen it repeatedly enough that I'd say the timer is a bit short, though, if it's that-
It is notable however that reloading the level-switch autosave would mean there's no enemies.
Enter map, damn enemies, reload, nothing there.
I haven't tried the reloading trick on a fresh map.