That doesn't happen now. Youtube changed the policy so that when a complaint is lodged the money goes into a separate bucket and sits there until the complaint is resolved. Once resolved the money goes to whomever wins the complaint so there is no lost revenue.
The only time this doesn't apply is when more than two people/companies are involved. As Jim Sterling found out if you have multiple companies making copyright complaints then no one gets any money as Youtube bows out of the advertising. Guess they don't want to get involved in lawsuits between multiple corporations so they decided if multiple people make a complaint against a video then no one gets any money (not even Youtube.)
"If truth is beauty, how come no one has their hair done in the library?" -- Lily Tomlin