That particular video has been cropped and edited. If you look at the YouTube or PINAC version, it appears the man had pulled into the C Store & gotten out before or as the officer pulls into the parking lot.
You can't say with certainty but it also appears that the officer came out of his car with his pistol drawn. Either that or he is very fast on the draw.
Here’s the whole video, he was already out of the car so basically what you have here is a cop shooting a citizen on private property.
https://www.youtube.com/watch?v=RBUUO_VFYMs