So, I'm just minding my own business when I get the quest notification popup that my settlement is under attack. OK - so i fast travel out to "Finch Farm" (one under attack) and all of my turrets start gunning down a cow. WTF? Cow dies almost instantly and the quest doesn't update - looking around there are no other hostiles in sight. So I go to open the inventory of the cow, and get this:

http://i.imgur.com/J1wcm8k.png

WTF? Synth stuff? - Well whatever, except, the quest STILL isn't complete: http://i.imgur.com/G8WwuM7.png

Googling the issue, I've seen these:

http://www.gamefaqs.com/boards/164594-fallout-4/72871537

https://www.reddit.com/r/Fallout/comments/3ssjta/spoilers_be_wary_of_your_settlers/

So apparently I'm not the only one. Anyone else?

I'm assuming there is a bug that spawns the cow instead of a regular hostile - pulling the wrong reference ID or something