The investigation has really hit the rails

This mix up, concerning the investigation of Russia’s involvement in the US presidential election, was heard on NPR.  It’s a mashup of “off the rails” (in a state of disorder or chaos) and “hit the fan” (become a scandal).  Not sure which idiom the speaker intended, as both could fit in context.  Perhaps the speaker had a mental image of the hobo catching a ride on a train and “hitting the rails”.  A tip of the toque to JoErin Mahokey for hearing this one and passing it on!

P.S.  Yvonne Stam, frequent contributor, added this additional explanation: “I would offer ‘hit the wall’ (reach a point of exhaustion) and ‘hit a wall’ (unable to make further progress) as well.”  Agreed!  Thanks Yvonne!