Your force must proportional. I didn’t make that law. I’m just telling you what it says.
So can you use lethal force in response to a touch? You betcha. Suppose you’re an old guy, and a crowd of yutes follows you while threatening you. Then one grabs you. A jury might well believe you thought your life was in danger.
But it’s not up to you or me. It’s up to the DA and then a jury.
Where there is spark, usually there is fire. The force feeding will stop soon enough.