Something strange

So i gave the Vanilla SP one more go, and what i discovered is strange, cuz i played it countless many times and didn't see it. When you get called by Juni to Cali Minor, you encounter one of FP7 survivors right outside NY>Cali gate. He gets shot by 3 Navy ships, and what i did, i shot them down. One of them dropped the "Nomad Prototype" weapon and i was all like . When i opened the cargo i saw a turret (attachment below). Anyone got this or what?

Yep, that one OP. Any clue what/how or any explanation? First time seeing this one after 7 years of FL

-Adding FL Vet quote from Husker to siggie-

Edit: Done!