VolantRedX, of course powerful capes are, to some extent, above the law.
Just like mob bosses are to some extent above the law, as are politicians, celebrities and other prominent figures in society.
Obviously they shouldn't be in an ideal world, but in practice that's exactly what they are. There are all manner of situations where it takes either integrity and determination on the part of the individual, or institutional pressure, for anything to get done that goes against the powerful person's interests.
The powerful person doesn't even have to push for it or request it, a lot of the time; people concerned about their reaction will smooth things over or brush them under the rug before the powerful individual involved even hears about it.
This happens *all the time*, in bureaucracies and organisations, in individual interactions, all across society. It's all the more understandable dealing with Capes, because just one Cape can change around the dynamics of a whole city in a few months (viz Skitter).