If you were given the Horizontal Gaze Nystagmus tests (HGN), a.k.a, the "follow the pen test with your eyes", did the officer do 7 passes?
(1) did he do a preliminary pass to check for any disability?
(2) on the second pass, did it take exactly 8 seconds, or did he go too fast?
(3) on the third pass, did it take exactly 4 seconds, or did he go too slow?
(4) remember, most people have some form of natural nystagmus; however, it eventually clams down after a few seconds, but an alcohol nystagmus doesn't. So, if the officer went too quickly, he did not perform the test correctly and may have seen the natural nystagmus and incorrectly come to the wrong conclusion.