Looking at these screens, and speaking as the faction leader I can see he identifies you as a Junker with foreign cargo. He gave you a few lines of RP, more than is neccessary for starting an engagement. You should know that Xenos and Junkers are bitter enemies, particularly so recently due to the new scrap bonuses. While a little rushed, it was the inevitable outcome of the situation. It would appear that you didn't realise he was an enemy.
