From Wikipedia:

Hanlon’s razor is an aphorism expressed in various ways including “Never attribute to malice that which is adequately explained by stupidity”

I am familiar with Clarke’s Law

Any sufficiently advanced technology is indistinguishable from magic.

I heard this corollary today:

Any sufficiently advanced incompetence is indistinguishable from malice.

Which is attributed to several people, but the most common seems to be Grey’s Law.