The judge was a she not a he, but that aside I think calling her "gullible" is a tad harsh. The role of the justice system, is principle, not to be vengeful and malicious but to be -- well, just. And to me at least that means basing decisions only on what is presented before you. Even if, having seen the initial pleas/ expressions of remorse etc, before the passing of the initial sentence, you thought they were lying through their teeth, how certain would you be of it? And anyway being personally certain is not the same as being legally certain.
While the current system is open to this sort of mockery, though, it seems to me that this is preferable to a system where legal guilt is equated with moral guilt. I'd prefer that justice implicitly assume that people are redeemable (or at least start with that assumption and be required to strike it down), and sometimes mistake people like these two as being so, rather than the other way round, and condemn the redeemable along with everyone else.