He is a lying turd, and since his lies are so obvious, either the authorities will start asking him some serious questions, or they have been told to refrain from doing so which plays into the US gov being behind this theory.
Do you not consider a third possibility: Japanese government prefers to just continue with the view that bitcoin has no value, and by ignoring bitcoin like this provides a massive SCREW YOU to all who lost bitcoins in MtGox, which suits their agenda?