Han Shot First - From the Phineas and Ferb Star Wars special

Han shot first!

No, Han shot second!

I don't know!

Third Base!

It was to make Han be a bit more of a sympathetic character, as he shot in self defense rather than take an advantageous shot at someone who hasn't fully aimed their weapon yet. Honestly, I didn't care either way, the scene played out the same, just the edit made Solo's reaction time a bit slower.