There are several instances when whistle-blowing has been diverted from its initial objective.
One perverse effect of whistle-blowing to the government is where whistle-blowers get rewarded on a percentage basis of the money recovered. This gives people an incentive to spill the beans. But it also gives them a motive to fabricate evidence in order to get the reward, or to tell on a project they have themselves been involved in. Normally planners of initiators of the fraud do not get the reward, but they are not always caught. Article in the New York Times on the subject here.
Another abuse of the system, is in employee suits against their employer to recover incentives/bonuses after they have left the company. Apparently, some unscrupulous lawyers tack on to their lawsuit allegations of whistle-blowing or sexual harrassement, because they claim it raises the temperature, and makes it easier to get a settlement out of court. There is a case in point of trying to get the lawyers to follow a code of conduct.