I may have encountered a bug with reaction fire.
According to this page
https://www.ufopaedia.org/index.php/Reaction_fire_triggersshooting and hitting an enemy that is turned away should make him spin around and reaction fire at you. If his tu + reaction value allows and if turning gets your soldier into his visual range. In the attached save I have not been able to trigger that behaviour.
The gal with the flag can empty all her tus shooting at the goverment elite without triggering reaction fire. If she moves in his line of sight with sufficiently low tus he fires, so this part is working.
I had another encounter a while back where this AI behaviour was definately working, but there was another bug. I shot a raider buzzard with LACC HE rounds. I found out that a direct hit would make her spin around and reaction fire, but an indirect hit (HE area damage) would not trigger rection fire. According to the ufopaedia page indirect fire should also trigger reaction shots, there should be no difference between direct and indirect. Unfortunately I have no save anymore from this encounter.
Edit: further tested the save. Shooting a goverment agent made him spin around and return fire (as it should). Hitting him in melee and walking away did not trigger reaction fire (this should trigger reaction fire according to ufopaedia article).
