The only take away here is that you have to treat malice and stupidity the same. The person in question either messed up intentionally, or is too stupid to do their job. You should fire them, or quit, whichever position you happen to be in.
Stupidity can also be more subtle. It's not always clear cut idiocy, there's a continuum between total and absolute head-desk stupidity, and ignorance or information blindness that's outside one's control.
Whereas malice is much less a continuum: the only question is, to what degree is this person an asshole, and when will they strike next? Intentionally and willfully hurting others is another world from anything unintentional.
The law treats it the same way. Hence, I believe it is helpful.
In any case, it's a razor: it separates illogical conceptual rabbit-holes from that which is more likely to be true.