Those are two possibilities. Another is that the government is the biggest player in the bond market and has unlimited funds at their disposal that they can categorize as Other.
But of course, that's illegal, so it would never happen would it. But at the same time, you and me will never, ever, hear from the bond vigilantes again.
Anyone who's been even an armchair observer of economics for 20+ years should know well how silly these conversations can get.
Just as one unimportant example: Bond vigilantes used to be a term you'd encounter regularly, when's the last time you heard it now?