Noah Smith still thinks financial crisis is a "random event"

"Failure to understand the cause" does not mean "These things occur at random". However, it may seem to mean that if you fail to understand the cause.

Noah Smith: Don't Forget What Causes a Recession

Why has the economy been growing uninterrupted for so long? Part of the reason is surely due to the severity of the Great Recession itself, coupled with the slowness of the subsequent recovery...

But there’s another reason too. The U.S. simply hasn’t been hit with any of the random events -- what economists call shocks -- that tend to tip countries into recession.

The first kind of shock, obviously, is a financial crisis.

Financial crisis = shock, Noah says, and shock = random event. Noah still thinks financial crisis is a "random event".