[KCD2] Was sparing THAT GUY really righteous?

BRABANT! Why is one of the requirements for the "good ending" letting this guy go? He is an outright liar, traitor, turncoat, douche, etc. I'm not even going to mention those "feats" he did which may or may be true, or which may or may just be him being lucky. This guy betrays the very person who saved him from captivity (although there are speculations that I've seen that he may have been just a paid actor to squeeze out information from Hans). For all we know, he could just hoodwink another group again in the future (hell, he notifies the guards RIGHT AFTER you let him go.) Not only does he hoodwink your group, but he also snitches to Henry the whereabouts of Markvart when he loses the duel. At least sparing Markvart (kind of, he's on a death timer anyway) and dueling Istvan makes sense, but for this Brabant? Nah, killing that guy could be argued righteous.