One of those absurd ideas that hits me out of the blu when I'm waking up.
Han's blaster fire in the trash compactor ricochets all the way up the garbage chute, bounces around the Death Star corridors, finally escaping via one of the hangar bays. It bounces off several celestial bodies, travels through hyperspace, and finally finds it's way to Tatooine, where it strikes the still smoldering remains of Greedo. Yes, they're too lazy to clean up dead bounty hunters in Mos Eisely.