Sprunk machines and water stands are supposed to revive your health to a certain level (I guess 50% of your health) so I don't think this is a bug since if you're able to use medkits after getting downed, you should be able to use sprunk machines aswell. But for real, the odds are really low that you actually get killed next to a sprunk machine or water stand, in my case I've never died near a sprunk machine.

