Homing rockets of Flechette Launcher and Hornet Barrage deal 0 damage to colonist head
Colonists (such as one under Tarnor's Oasis Colony Spaceport bridge) normally take 3x damage on headshots. Hornet/Flechette does deal normal damage to bodies, but no damage at all when hitting the head. With the default top-down perspective, perhaps this randomized trajectory stuff has the most chances of scoring headshots...
Ok, here's what I think is happening:
Since colonists are in the marine faction, they avoid explosive damage that isn't within half its radius of their center.
The radius of a rocket is 50 units (red circle), and a colonist is about 72-74 units tall. So 25 units (green circle) below their neck is still above their center.
Unsure how to fix this, but that's why it's happening.