The point here is that an audio tape is not proof, and reading a blog, or newspaper article, and certainly believing it is lashon hora at the least, and possibly motzei sheim rah.
Is a Rav automatically innocent? No. But 1) he's not automatically, guilty, either 2) by making assumptions like that, we bring ourselves to a point where we don't trust any rabbanim, and then where are we? Especially since, when everyone is ready to pounce, it becomes even more difficult for rabbanim to takeany action without causing all sorts of issues, including a witch-hunt-type situation.
As an aside - I have friends who've been abused in various situations, and it's horrible. I'm the type that feels an urge to take a baseball bat to people who do that. However, as a counselor in summer camps, I'm also aware of the flip side - there have been stories where campers have accused counselors of doing things, and it was later admitted that the claims were NOT true. It's kinda scary when kids realize how much power they have over a counselor...