due to the fact that irregardless is a negative to regardless which is already a negative and two negatives make a positive, "ly" makes it a negative again. meaning mindless or having shown no regard
i ate your cereal irregardlessly of the fact that it was your cereal not mine
"ly" does not make anything a negative, dumbass. It makes it an adverb.
He posted a correction to another definition, irregardlessly of the fact that you're not supposed to do that, and also the fact that "irregardless" is a stupid word.