With all due respect, I think there are more important things in this world to worry about. For instance every time I go to my auto garage, the mechanic, every single time approaches me with a long wrench in his hand... Should I be concerned?
Seriously, if you really want to know ask him! Why would you ask people on this forum who aren't there, don't know you or the cop or the situation?
I'm sorry to say it, maybe I am in a bad mood tonight but what is with all the silly questions on this forum? Can one not think of anything better to post? Are we that preoccupied/paranoidnwith police that every one we see must be out to get us? I joined here for some serious discourse, and education. I am looking for questions pertaining to guns and real world carry and politics and self defense and the like. Not to be fortune telling what some cop may be thinking if he is resting his hand on his gun in a gun shop... The key word is resting. As to the OP, did he jump up and shout at you not to move too?