I don't think this sentiment is so wise as its popularity would lead you to believe. I have no reason to believe that most bad things that people do happen entirely by accident. Further, I suspect that the first line of defense for anyone who's been caught doing something naughty is to play dumb, and I see no reason to make it easier to get away with murder, so to speak.

I believe that is an accurate statement, only when applied to the actions of one individual.

When speaking of the actions of corporations, governments, or groups of people working in tandem in any fashion, malice needs to be your first assumption.

Stupidity can be dealt with after you fix the problem, but malice will not only make the problem worse, but will also make dealing with the problem more difficult.

Oh man, china would like to have a word with you about that statement.