That isn't a bug. That's player persistence saving it, like how it saves your tools and velocity and position.
You don't understand how my script works. It overwrites the datablock's max damage. When they spawn, it saves the actual damage. The events overwrite the max damage. When they die, it makes that data block return back to its original health it was. When they leave, it will not reoverwrite the datablock. So its stuck at a max damage it was set on the event. This will be fixed when I get home though.