In context, the post that person was quoting suggested that US police should take note that the suspect was taken down without firing a gun. It was a cheap potshot at US cops (or at US gun politics or both), since the use of lethal force clearly would have been authorized here. Hence the cop using his or her vehicle (hitting a suspect with a squad car is almost certainly using lethal force). It was frankly a poorly thought out post, and the person was calling the original poster out on it.