For my current job, I had a sim assessment in an A320, while at the time I was rated on a B747-400. I had no previous experience of an Airbus and no breifing on the landing from my assessor. I managed a reasonable landing with out a snag.
But if a pilot was faced with an emergency landing in an unfamiliar type, he would probably opt for an autoland. This is asuming he could work out how the automatics worked. But the differences between Airbus and Boeing Master Control Panels aren't too great, and you could probably get someone on the radio who could guide him through the setup.