Not sure if this is a bug or just AI's being AI's, but the fighters appear to enjoy chasing each other out of the gravity wells and into open space while they are dogfighting.
I've also seen in random cases of a single fightcraft (enemy) surviving and apparently respawning WAY outside of gravity wells (but marked as being in orbit of the planet) causing friendly fighters to chase it. No other enemy units or structures within the gravity well.
Also, I don't know if it's just the small distance between the two stars in the one map, but it says my ships can jump to the other star even without the "Long range jumps" researched.
edit: Meaning prowlers actually did the jump, and it confirmed a capship as being able to reach the other star.