Mayor-in-Waiting Pat Mumford refuses to get off the fence in the CATS-Parsons Transportation Group spat over who messed up the $427 million South Blvd. light rail project.

That won’t do, Pat. Either CATS screwed up — and did so ignoring eight years of warnings in the process — or Parsons’ design suddenly went bad just as CATS was up against a hard budget cap.

Hmmm. Which one could it be?