The procedures were just as procedural, and Old Tang's main issue in the case was whether Liu Shangjin truly had the subjective intent to cause harm!
"We all know that to establish the crime of intentional injury, it's not only necessary to have the objective act of using force and causing harm, but there must also be subjective intent!"
"In this case, the victim Liu and the others forcibly invaded our client's residence, intending to take him away; during this process, Liu grabbed our client's arm and forcefully dragged him."
"A comprehensive review of the evidence and witness testimony can confirm that our client's action of grabbing Liu's arm was to push the other party away to obtain freedom, not to harm the other side."
For a legal veteran like Old Tang, this line of thought in criminal cases wasn't difficult, the hard part was whether the court was willing to listen to your reasoning.