mister geezer to make sure you understand what a critical engine is let us clarify a few things.The failure of an engine which causes the most amount of YAW is known as the critical engine.Hence in propeller aircraft (2 engines)and contra-rotating props (in the same direction) the tip of the blade going down closest to the fuselage has a smaller yaw moment than that of the other prop with its downgoing prop (because it is closest to the fuselage .) Hence failure of the engine with the downgoing blade closest to the fuselage will cause more yaw because of the longer yaw moment of the other engine.From memory it is usually the left engine in contra rotating props.
Now then what about Counter-rotating props and jet engines? All being equal and wind straight down the runway there is not (theoretically a critical engine) because failure of an engine either side of the aircraft will cause the same amount of yaw.
Now what if there was a direct crosswind? say from the left. The left hand engine fails, yaw has now been created from the right engine to bring the aircraft nose to the left the left crosswind exaserbates the problem with the wind striking the tail causing shuttlecocking AGAIN to the left. HOWEVER mr Geezer if the right hand engine fails the aicraft yaws right but shuttle cocking brings the nose to the left hence less of a problem. Hence the left hand engine is the most critical and visa versa for a Right crosswind. So as you can see there is such a thing as a critical jet engine.Sorry to all those who think i am teaching people to suck eggs this is not aimed at you.But for the Mr. Geezers of the world.