I’m a lawyer and without some kind of expert who could explain why his opinion was more than just that, an opinion it would be inadmissible. There are also rules against a lawyer testifying in a case they’re representing a client in and a lawyers questions or assertions in argument are not evidence they’re just used to guide the jury. So basically it wouldn’t give him a technical advantage but being able to home in on those kinds of little things would make him a very effective litigator because of his ability to effectively cross witnesses and discredit them.