A Person with a Negi'a Cannot See Straight [Sometimes That Person Is You]

Why did Dassan and Aviram say such a weird thing, by talking about Moshe blinding them? We can suggest that perhaps Hashem caused them to spell out their very Chisaron; that they had a Negi'a, which is: שֹוחד bribery; and: הַשֹחַד יְעַּוֵר bribery blinds; maybe this would cause them to do Teshuva. And like they say in Novardok “Negi'a Gaon”; you are a Gaon in your Negi'a; and you can’t really see straight unless others [without Negi'a] explain it to you.