I spent 24 years Army....mostly aviation maintenance, instructor, and graduate of Safety Center and later Crash Investigation schools at Ft Rucker. For over 7 years I was sent TDY to various crash sites to investigate, guard, photo document, interview witness and air crews, write opinion and fact based reports as part of a team.
I am not trying to find a way to excuse any actor in this event....
Based on photo evidence I have no good theory how that happened in forward flight.....however at a hover, any object (FOD) of weight might have rotor wash blow it into the leading edge of the sync elevator
HELL for all we know from the reporting....This crew failed to pre flight an on landing post flighted and made up a story to account for the aircraft damage......
90 percent of the pilots I met were above average smarts and good honest humans.....the butt heads got FEB* OUT and went to work flying life flight or power line or TV crews....less than average ability or ethics got them *Flight Evaluation Boarded out of the Army
In an urban area, I have never heard of a weapons assault from above, but I do not believe my knowledge is any indication that it never happens...I know that no "from above" incidents ever happen in RURAL areas...duh!
I do know and have investigated shots and hits to Army aircraft from below in the greater Ft Hood Texas area...never did find the shooter(s) and most were relatively small caliber