Okay, so I guess this is a problem with vanilla ArmA 3:

"No default vars in bin\config.bin/CfgMovesMaleSdr/States/Acts_UnconsciousStandUp_part1.variantsPlayer
No default vars in bin\config.bin/CfgMovesMaleSdr/States/Acts_UnconsciousStandUp_part2.variantsPlayer"

We had some problems with Xmedsys earlier, but we deleted and edited some lines of codes in there, so that fixed those problems (those problems being, you had an incredibly high chance of getting instantly killed from a headshot, despite X39 meaning it should be only 1% chance of insta-death after a headshot, and you were sometimes reading "Patient is unresponsive" when he's clearly up, which randomly kills you after a random amount of time, because when ArmA goes through the script, it'll find out that "Oh, you should be dead!", and then kills ya)

UnconsciousStandup is not anything I can see is in Xmedsys or any of the other mods we have on our server.

Basically what happens, is, sometimes, when you're knocked unconscious, you randomly stand up, but you can't move. So that medics think you're up, while you are really bleeding to death)