He can NOT shoot you for not following his instructions. Deadly force can only be used as a last resort to prevent the suspect/perp from causing serious bodily harm or death to the officer or persons/civilians around the area.
If you have a disability calmly explain your limitations. If you start acting like an ass, ranting and raving about your rights, expect to be treated accordingly. Failure to follow police instruction, resisting arrest, tripping and falling and hurting yourself.
A little bit of respect goes a long way, and not making the officer feel threatened, or feel that you're a threat will make it easier on both of you.