Negligent building design case dismissed for lack of expert testimony

Benjamin Tappen was staying at the Wyoming Hampton Inn for a family wedding when he slipped and fell on the tile directly in front of the elevator, suffering injury.  He alleged that the hotel was negligent in responding to water tracked from the pool across the tile foyer to the elevator, and that it had negligently designed the building. 

Since Tappen could not prove how long the water was present--or that the hotel staff "reasonably should have known about it" and responded--his negligence case was dismissed.  The Court of Appeals upheld the dismissal of his design theory--that the pool entrance should not have been located directly across a tile entryway from the elevators--because he had not listed an expert in building design.  This seems like a mis-application of the latter rule, since it doesn't seem as though an "expert" is necessary to address such a common sense issue, one way or the other.