Cyber expert criteria

Hi,

      Is a non computer engineer who run cyber cafe can became police cyber expert ?

       How can we challenge it because the claims made by that expert is wrong.

       Is only proving that he is non-IT enginner and non eligible for this case will make wrong evidences null in front of judge or not or we still need to take it further and provve that evidences also worng or misrepresented ?

       Can we take any legal action against this expert ?

Thanks