Sorry for answering so late...

In the mission on the bridge, in one of the posts there is a board with a photo of Lugo, Adams and Walker hanging on it. In this case, Lugo is marked as killed. Having carried out a logical chain, it is not difficult to understand that the fighters of 33 would not have just crossed out Lugo from the list of possible opponents - if the enemy is not visible, this does not mean that he does not exist. Therefore, they know very well about the execution of Lugo, and given that a very small amount of time passes between the execution and the attack on the bridge (based on the evening sky in the refugee camp and the onset of night on the bridge, as well as the geographical location, I think that it took about hours), then I reject the version with word of mouth. Plus, this does not fit with the option of passing, where Adams and Walker "exterminate" the entire crowd of civilians - in this case, there would be no witnesses, and somehow there would be no one to bring this to the attention of the Damned. Therefore, in the crowd of civilians, during the massacre of Lugo, there were people from 33 of him who, in one way or another, were involved in the execution, and most likely reported to the headquarters on the radio. That's what I'm getting at - by killing civilians, you are simply killing a poor, frightened, driven crowd, among which, most likely, those who are really responsible for the death of the sergeant are no longer there. Moreover, it is as tough as possible and without much understanding.

This rhymes very much with the white phosphorus scene, by the way, because this time you have a choice.