If you start the expedition with Aegis, but then steal an Aegis Patroller without being detected and join the pirates, all expedition civilians (including Ladelman, Seeger and Professor Oldfield) remain friendly (blue).
Moreover, if this is done before delivering the Phil's arm, if you stealthily return to the camp with the arm and go to the Arch Keep entrance, Seeger goes to the door, and you can trigger the Keep opening cutscene despite Briggs and Oldfield not being present (their dialog is said by "Unknown").
If you are seen by Aegis or kill an Aegis trooper (even if unseen), the civilians become hostile.
