Regardless of when it happened, I always thought it was an unusual excuse for Han to use to leave the Alliance. Sure, you've got gangsters trying to collect a debt on you... but now you're in the military. If the bounty hunters want you, they have to fight through the Rebels first.

I get that he ran into a bounty hunter while on a mission, but any mission he goes on for the Rebels is inherently dangerous anyway, because of the risk of encountering Imperials.

Besides, he should also be worried that Darth Vader would be hunting him just as fiercely as the Hutts, since he helped blow up the Death Star.

Rieekan says, "a death mark's not an easy thing to live with." But as resistance fighters, all Rebels are essentially marked for death.

Does that make sense?