Do you know, accidentally click on Google Adsense will counted as no click. So, if you clicked two same adsense unit, the second click will have no effects, at least, that's how it's works on some site. It's proved with the $0.01 at the picture below
What about clicking the same advertiser which has different Title? It's treated as Low Pay Keyword, or around $0.01. However, it is pretty fair since the clicker saw the same site. This is fair for the advertiser and publisher, so however, Accidentally Click will have no effects on the publisher. It will remain fair.