Well, maybe it wasn't a hacker. The ATV seems to be horrible broken in terms of hit detection, you can shoot at someone driving it point blank without any damage registration on the driver or vehicle. I experienced this myself multiple times. The Winchester counts as shotgun in this mod and while they are quite underpowered they tend to knock you unconscious in one hit.
Well the crowbar spawnrate can be adjusted. Locks aren't meant to completely prevent anyone to steal your gear, but it adds a level of security. Breaking a lock should take some time and being quite loud tho. It also adds to immersion. Can you really trust all the people you tell your lock combinations? Would be awesome.
Well they hacked the mod, despite of their popularity or intelligence, they (and the admin/hacker) need to be punished like every other cheater. No mercy for hackers, even if they are popular YT-Whores or the fucking president.
With the underground housing being announced I would love to see some simple lock mechanics in the mod/game. How about finding combination locks in factory tier loottables (very rare)? They could be used to lock chests and instance access points (trapdoors, or whatever will be used for the underground housing). You can choose your combination (3 or 4 numbers) and it will lock the door / chest. To access the locked object you need to either know the combination or break the lock using a crowbar (move the crowbar in the toolslot). All combinations a character created could be saved on a note, which can be looted by anyone if the character dies. This would provide much more depth to the game and prevent some random people without crowbars to steal your stuff and occupy your safehouse.