On Confidential this week, they did a feature on the making of that commercial, and the guy slipping was an accident.. they decided they liked it so much though that they had to use it in the finished product. Ah, the joys of commercial making.
Surprise matches can always be made into great feuds. Why the hell do you need a "build-up" before the first match in a feud? That is silly- feuds in wrestling make sense more often if it is based on what happened in the ring.