i dont think its an error, we already had threads like this before.. i even heard someone had a a 16.9 or 17$ click.
i had a click last week on one of my video game sites that was around $15. have yet to figure out what the heck the ad was for...my average $/click for that site is $0.064 for April. i have seen some bad ad targetting this month with adsense so maybe that was the cause...