“How To Get Officer's Testemony Discqualified”

OK, so if the officer does not show up you get to walk, which means if you can get his/her testimony/statements nullified officer's presence is irrelevant.

Now, lets assume you ask him/her a question to which he/she provides a wrong answer to, how do you go from there asking the JP to disqualify his/her testimony since he just provided falls statement?