On the only occasion he failed an elderly pilot, for confusion in his case, this individual promptly obtained his medical certificate elsewhere.
Who was the regulating authority
Skol? In the ones that I am familiar with the doctor who failed the pilot is obliged to file that information with the aviation authority concerned, so when the second doctor sent in a 'pass' questions would be asked and the certificate suspended until the AA were satisfied that the pilot was fit, or otherwise.