After spilling lots of champagne in first class, the Boeing pilot will eventually figure out how to manage things on an Airbus. But it will be ugly. Then he will make a heavy landing at the end because of the little surprise that mr. Airbus has in store for him during the last 50 feet.
As an aside, even trained ex-Boeing pilots have some trouble in the beginning controlling the Airbus. The latter requires very fine wrist movements on the side stick, something which is new to the 'conventional' pilot.
And an Airbus pilot flying first time on a Boeing? He will have a very hard time with the concept of trimming, flying level in a turn, manual thrust, trimming, mechanical seats, trimming, yawing and banking, trimming, trimming, trimming, etc. And he will probably depressurize the cabin and overboost the engines in the process.