Could it be a bug? all of the sudden i hear Paladin Danse saying, "I feel we are being watched" and started shooting the Vertibird cuz they attacked us first, what's going on? I dont want to start attacking the Brotherhood and then next thing I know, they'll probably hate me and along with Danse perhaps. Did anyone else experience this and how did you get around it?

Edit: I just found out myself, I ended up loading the file twice (because they attacked again) and hiding from the Vertibird so they didn't see me. In other words, I just ignore them and when I went to another map area, theyre not attacking anymore. Whew! Good thing I didn't shoot back. Saw other posts from other people having this problem but they kept shooting the Vertibird and now theyre hated with the Brotherhood. Don't want that happening, though they do drop nice stuff xD (I mightve attacked upon curiosity *cough) Anyway, if anyone else get this bug, don't attack!!! hope this helps in the future for others. It's just a bug that happens probably every now and then. Hopefully rarely, sigh.

I hear the gunners have some havnt seen it myself.

The Gunner have vertibirds. At high level they will spawn near Gunner camp.

it's usually stray bullets. Is it possible a recent bullet of your's or from Danse could have hit a scribe behind a building a block or so away?

No I was using my melee weapon at the time, so no. I honestly think its one of the bugs because I've googled answers and people are having the same problems too. But that does sound like it could be a possibility that will happen in the future so I'll keep that in mind, thanks!