Most likely nothing is being covered up, it is just the Minnesotan way. Excel Energy/State Regulators probably only released the statement to beat the Federal/NRC report on it since that would make it look like they were hiding something. To succeed here you need to understand the Minnesotan mentality, the so called "Minnesota Nice," you will be punished for making people needlessly worry so you don't release a statement about a leak at a Nuclear power plant unless it is a run for your life situation, if it turns out to be no big deal you casually slip it into the conversation a month later.