Why is Edward Deegan hostile?

And who is he anyway?

I just entered Bunker Hill, minding my own business, and the guy starts shooting at me. I've never met him and I have no quest involving him, most importantly I CAN'T KILL HIM. Whenever I deplete his HP, he goes down for a few seconds before getting back up and starts shooting me again.

I can't do anything in Bunker Hill because all the NPCs keep running away from me, yelling "It's not my fight".

It's not mine either!

I found this reddit post about the same issue here.

Apparently, as stated in a comment, I killed some robots around Cabot House just prior to entering Bunker Hill, which made Mr Deegan hostile towards me (even if the robots attacked me first... I didn't even enter the place either, they probably just got caught in a crossfire between some raiders and I)

I ended up waiting two full in-game days (as was suggested in the link provided) and Edward Deegan is no longer hostile.