My understanding of the DC Faceless' dialog is as follows:
* Start with 0 attitude points
* Add 1 point if you finished the Faceless recon mission near Foundry, unless the Faceless near Foundry are at war with you
* Add 1 point if you did not kill the Faceless mindreader in Buzzer's shop, unless the Faceless near Buzzer's shop are at war with you
* Add 1 point if you released the captured Faceless in the Black Crawlers' hideout, did not drop him, and did not attack him
* Remove 1 point if the Faceless group in Buzzer's shop are at war with you(for example, if you attacked them)
* Set the points to -5 if you released the Black Crawler Faceless and then attacked him
* Set the points to -5 if you killed the Black Crawler Faceless by dropping him
* Set the points to -5 if the Faceless group near Foundry are at war with you(for example, if you attacked them)
The dialog files themselves are kind of annoying to read by hand, so you should distrust this next part. But I think I see checks for:
* If the attitude points != 3, then something
* If the attitude points > 0, then something
* If the attitude points > 1, then something
* If the attitude points > 3, then something(this might refer to negative numbers? Or there might be one other way to get a +1 point to attitude that I didn't catch)
If you unpack your save file, the bytes immediately to the right of 'loc_dc_flo_attitudeCalculation' should have the value of the attitude points above after you talk to the commander.
In other words, I don't see a direct reference to checking whether Buzzer was allowed to die. It's possible that saving him marks those Faceless as being at war with you, in a manner that escaped my casual inspection, which would have the same effect.