Ben tried to shake her conviction.  He pointed out that several dozen other persons were known to have seen Smith - guards, internes, male nurses, the captain and crew members of the Champion, probably others.  Quite a few of that list must have seen this newscast - or at least the administration would have to assume that some of them would see it and spot the substitution... if there had been a substitution.  It did not make sense - too great a risk.