Are you sure about that? Because it seems to me like I've shot the Higardi soldiers on accident, and gotten them angry.

The various factions have reacted to accidental hits differently. If i contribute any damage to an Umpani, Rapax (when they're green) or T'rang who is then killed, they go red on me. Higardi and Lay Brothers haven't yet, nor Trynnies, unless the damage i contributed was intentional. Every time i've targeted a green dot, it went red immediately upon being hit.

try hitting them by range weapon not melee weapon, they'll go nuts at me when I use melee but never range.

Thanks for the tips everyone. I did rob the bank via the jailhouse, that must be it. Never mind, will finish the game first then do it differently. Anyway, picked up so many goodies and never used them; always counted on my team's abilities to fight the battles.
Next round will try something different....