Meaning of "Hitch Back"
Solution 1:
This is the closest interpretation of the phrase "hitch back" -
- The blaster is at his waist, meaning he moves the bottom of his jacket back so his hands can reach his waist.
I think it's basically because he is hitching his jacket back, meaning, moving back his jacket to reach his pocket (of course the jacket would come in the way of the pocket!). If he had to remove it from the front, he could technically just slip his hand right in without the need of hitching back (or pull forward in this case) his jacket.