Third player encounter, strange ending

Playing on Atlanta 121, I met a group of three players on the docks at Balota. One had a hatchet and the other two were unarmed. I was low on blood and dying (from becoming bored and killing about 50 zombies with a pistol and rifle), so I gave out the M19 I had been saving for a friend and the 5 clips of ammo for it. I wasn't shot on site nor hacked to pieces, so I trusted you guys. Your "leader" was talkative and friendly, and although none of you had blood for a transfusion I desperately needed I still decided to help you guys out and travel with you.

We hit the military camp northwest of Cherno, finding an AK47 inside. We were seemingly doing well, ready to head to Cherno to get me some supplies. I felt bad for the fourth, unarmed player and (despite him not talking once, unlike the other two) I decided to sacrifice my Lee Einfeld and 5 clips of ammo so he wouldn't be unarmed. After a small encounter with zombies trying to enter the camp and while we were preparing to leave, I noticed the fourth person had slipped off unseen. I heard him shooting occasionally, but I didn't think for a second we were in danger and he was firing at the zombies, genuinely helping out. I wrote off a fleeting thought of suspicion, assuming you were still with us and preparing to head out until...

a loud crack rang out, and a "oh fuck" reached my headset. I looked over to see the main talkative leader, the new friend I had just made, slumping forward and dying, and the person he was bandaging scattering with his M19. I spun around to try to acquire our new foe's position before yet another crack rang out and I was greeted with the familiar hourglass.

I don't know what happened to the other friendly in my group or if he survived with the gun I gave him, managing to conquer a rifle with a pistol. Hopefully he did, as I hate to see generally decent people betrayed by those they trusted and helped. To our murder, I guess you felt you needed to do it to survive. It happens. But being killed with my own gun is certainly a new experience to me. Maybe something useful came from my body, but I was running out of everything so I doubt it.

Atlanta 121, I took a break to type this really quickly but I'm headed back in now. Not sure if any of you read reddit at all, but I felt like sharing anyways. Looking forward to hopefully meeting up with you guys again, although one for a different reason...