Joined the forum to report this exact bug because it was fairly major. It happens if I fight the goblins at the entrance of the camp and I engage in combat with the ones just inside - pretty much as shown in the above screenshot. Didn't happen to Wyll's imp; it was my ranger's raven that was registering as hostile. If I kill it, combat ends, but anytime I summon a familiar again, even outside of that zone, it registers as hostile. I can still control it, it is just flagged as hostile and will trigger an attack of opportunity if it moves out of melee range from any party member.
To add a bit more: if I end everyone's turn, and it comes back full circle, I can no longer end turns until the familiar is killed. In the little pop-up window that shows whose turns are done, two ravens appear.
I ended up just using the worm to make my way into the camp (and getting judged by Wyll...).
