I recently did a wedding where I put a Zoom H2 recorder on the groom, fed by a lavalier. Since the lavalier is not very sensitive, I set the Mic Gain to High, which was perfectly fine when I did tests with the groom talking and me listening through headphones.
Problem is, in my experience so far with weddings priests were usually soft spoken, and maybe raised their voice a bit but nothing crazy. In this case the priest was loud as hell, yelling most of the ceremony, and even though he was about six feet away from the groom, when he yells past a certain volume the lavalier produced a hard blow noise that sounds horrible. I'm sorry that I don't know the technical term for that, it sounds a like a loud PLOP.
I loaded the file in Audition CS6 and tried different things, but none seems to work. Can this be fixed at all?
If the noise is of the mic overmodulating, then no, it cannot be fixed completely.
One thing you might want to attempt in order to lessen the effect is to look at it in Spectral View and see if you can use one or two of the tools available to lessen its effect.
If it's a loud plop, and there aren't too many of them then there are a couple of things you can do to reduce the effect of them, even though you won't fix the problem completely. Spectral view won't help you very much though, because these usually involve a very low frequency shift at an overload level, and it's this effect you need to get rid of.
First thing you do is to use a high pass filter to get rid of everything below about 100Hz or thereabouts. This alone will probably improve the situation a lot. Then, on the bits that are still bad, highlight them and apply Auto Heal to them, possibly more than once. Beyond that, there's not a lot you can do, short of getting the priest to learn to ADR himself, and fixing it that way. This is something that Audition CS6 is now very good at!