I get that provisional patent apps don't start the 20-year clock.
My understanding -- and please correct me if this is incorrect -- is that the exception for this is IF a situation arises where the patent owner is actually claiming a benefit from this provisional app, then the filing date of the provisional app does kick in to start the 20-year clock.
And in WDDD's case, they are very much claimin a benefit from the 296 provisional app as it is necessary in order for that demo that was made public in MAY-1995 to fall within the 1-year window prior to filing.