First resist the application under S. 311 Cr.P.C. on the ground that he is trying to bring fresh evidence on record which he deliberately neglected when opportunity was given to him to bring his evidence and also put allegation that he is trying to move the clock back. Despite these arguments, by levying some costs, his application will be allowed.
To contest this fresh evidence, first you have to cross examine his doctor and also simultaneously file an application in the court praying for giving him direction to undergo tests before the competent government doctors' team.