@Lord Drakyle I suspect that the judge is a witch because it seems too risky what he did imo, nobody knew anything about who the enemies were, but maybe he did because he suspected Alistair was a witch, but unfortunately we can't know for sure if he was town or witch.
In my opinion, if the judge is town, he might have been wrong doing such a thing because is too risky but maybe not, i don't know.
If the judge is a witch, then he simply does so to help his team, killing those with more experience.
Maybe Alistair was really our enemy or not, unfortunately we do not know that atm.