There's this cool bit in the Xena episode of The Simpsons where Lucy Lawless explains to her fans that any time something occurs in Xena that is incongrous, anachronistic, or plain makes no sense, the explanation is "A wizard did it".
DC developed a similar philosophy some time ago, and every time they have an Event they use that as an excuse to cover any continuity screwups up to the current time. After Infinite Crisis their excuse was Superboy Prime reality punches, but even they seem to realise how weak this was so within a year they came up with Mister Mind munching on the multiverse to explain away anything that didn't make sense. Unfortunately the main thing that didn't make sense was how someone, regardless of how powerful they were, could alter reality by hitting it, or how a giant space bug could eat an intangible concept.
Marvel got onto the bandwagon somewhat later, and it has to be said that while their excuse is an epic cop-out, it's a lot less metaphysical. Anything that went wrong/didn't work so we want to undo it/was plain stupid and made no sense: A Skrull Did It.