I've been reading v47 of the Mark Twain Journal and just came across
Excerpt, "The Brooklyn Story of Mark Twain's Innocents Abroad".
Apparently one Stephen M. Griswold claims that Sam missed the meeting
with Nicholas because he'd (Sam) had been out partying that night before
and did not get back to the ship in time. I don't know but this sounds
a bit like after-the-fact sour grapes to me. We do know that a number
of the passengers resented Twain's portrayal of the journey. I suspect
Griswold may be one such person. I would like to hear of any
clarification of this matter.