This is a typical disgusting tactic by cops to issue (sometimes conflicting) orders (e.g., "Don't move! Raise your hands!") that result in the person moving in a way that could be interpreted by the cop (and the courts) as resisting, suspicious, or threatening to the cop.
This is not just about a bad cop, but also about how some cops are trained.
The correct approach from a safe position would be to engage in conversation with the driver which doesn't call for him to move. Answering questions about if he has a license and where it is located would allow the cop to determine whether the driver's movement to get it would be threatening. Asking the driver to slowly get his license would also indicate that sudden movements by the driver will be considered as something other than getting a license. Until cops and their superiors are penalized for using such tactics, they will continue and more innocent people will be shot or killed.
Then there is always the "Stand down now!" order to add further confusion to a person who may not have a clue of what is occurring.