And the radio recordings are missing due to equipment failure, conveniently. It seems that missing recordings happen all to often in disputed cases...
In any case in which the police have equipment and it malfunctions, the absence should be treated as proof that their opponent is truthful. Otherwise, how do you eliminate an incentive to destroy the record? If the guy says you knelt down and invoked evil spirits and your dash cam "fails", you will be treated as if his assertion is proven. Now that of course would not apply if the guy claims you beat the crap out of him and his physical condition shows you did not.
Recordings belonging to a private party, OTOH, should be theirs to reveal or not at their option (secure in their papers, etc.)