Wisconsin Election Integrity has a good article explaining how well-meaning election officials can be opposed to post election audits.
Oddly enough, it is not the risk of a miscounted election occurring that causes their fear; it is the risk of a miscount being detected. Most computer-dependent managers–not election officials–realistically expect that if they do not catch a computer error, someone else will. For them, routine audits reduce fear. But miscounting voting machines don’t blow up like space shuttles, and candidates cannot take voting machines out for test drives between elections. Therefore, in the absence of post-election verification, election officials have no realistic fear of anyone discovering a miscount. The idea of an audit has the opposite effect on them: their fear goes from nothing to, well, something.