Not a CO diversion, but an Air India one...
Boarded a 747 from BOM to RUH. Upper deck, first class. Half way through the flint, captain comes on and says that we're turning back. Apparently one of the engines had stopped functionining. We turn around and land in BOM late at night. F passengers are put up in the Taj hotel.
Board the next aircraft at 9am the next morning and safely make it through.