I heard similar but haven't found a "no, it wasn't a monkey" article yet.
Digging a bit deeper, they appear to be running with very little margin, if any. Meaning redundancy and protection against cascading failures is limited.
Fixing the real cause is expensive, so it's often easier to just blame the trigger—though admittedly in this case it makes for a great headline. :)
It's not like the monkey deployed special monkey skills beyond "occupy space while being electrically conductive".