The $99 test is an entirely different type of test, an autosomal test.

There is no reason to think that the results are incorrect. You can ignore the 12-marker matches. You should go to the Aker public site and compare your results to the modal for the group he is in. A match with one person may simply be random. His or your ancestors may have had mutations which made you closer matches. However, it is always possible that there was a non-paternal, but it could have been fairly recently or a long time ago.