of something that does not have a clear legal definition. All he needs to do is listen to someone he believes have better credential. Like it or not Xiao is seen with better credential becasue he is a professor but the defendent had not done research for years. So it is totally acceptable for the judge to rule against the defendent for this matter in absence of powerful witness with better credential than Xiao. Winning a legal battle takes startegy and resource. You can't take it for granted just because you believe you are the good guy.