It's a terrible gotcha. It's only effective on people who already agree with you.

Imagine a town council meeting where someone is proposing a $25 fine for crapping on the sidewalk. And a libertarian pops and screaming "You're saying you want to use violence up to and including murder to keep our sidewalks clean!"

Again technically there is a hypothetical chain of causality from sidewalk crapping fine to bodily harm/murder, but no one other than another hardcore libertarian is going to be convinced by that argument.