IndianaDean:
Nope: The court transcripts say that for once the move was correct. Virgil had obtained the shotgun from the Tombstone Wells-Fargo Office prior to the fight when an excited citizen told him that Wyatt was about to take on the whole cowboy crowd at the local gunshop, where they were stocking up on extra ammunition.......
Ya really should read the testimony, it's much more interesting then any fiction.
Edited to add: Doc did indeed have a revolver, described as nickel plated - and the finish played an important part in the real story. In an unrelated fight he was described as having a ".41 self-cocker," but this may or may not be the one he used at the big shootout. As a side note, he carried it in a cross-draw holster.