Since there's a chance of being charged with brandishing and / or other violations at the state / local level, I'd advise reporting the matter to the police before any other party has the opportunity to do so, providing basic ID and information, (as to your being the "victim", any witnesses, any evidence, video, audio, etc) and then rely upon advice of counsel before any statements since you have more than a zero chance of being charged.
I'll leave it to BBI and other state and local LE to fill in the gaps as it's something they would have much more expertise with.
There's nothing civil about this war.
Yes, in addition to the more detailed reporting of whatever crime you were a victim of that lead to the escalation. Serial numbers for items stolen, etc.
I wouldn't assume that was the reason. Especially on a confusing scene, sometimes there's just overlap because an officer doesn't know it's been asked by someone else. If it's serious you're likely to have at least a uniformed officer ask for basic "what happened" and then a detective ask more detailed questions. You might get a supervisor asking you questions if an officer was involved in any way, such as a use of force.
That *could* be the reason, it's just not how we would do things. You could probably just say "I gave a statement to that officer over there" or something along those lines and see what the response is, then use your best judgement from there.
Sorta around sometimes for some of your shitty mod needs.