Clearly from a policing standpoint there are issues with this arrest.
1. tactics are crap based on the information the cops had, which was he was armed
2. Handcuffing strategy was out of the "Things you don't do when you have 3 officers available to make an arrest
3. Deputy lied in his sworn affidavit. Even if he misinterpreted the leg sweep and thought the suspect pushed the Sergeant, the conversation afterwards of what charges to apply would have cleared it up. So in my opinion it was no mistake, it was a blatant lie.
That should be 3 deputies out of a job. Their Sheriff missed a golden opportunity to address the issue of lying by sending the message it will not be tolerated. Instead, he condoned it. They will lose the lawsuit. And there are cops with credibility issues working the streets. This right here is what is wrong with policing.