I didn't take it that he was blaming either - rather, putting each on notice about how he felt treated by Customs in Italy such that they'd be aware of the incident.
@Neecy808
Can you clarify a bit on your comment "It appears that Celebrity had 'no tax requirement for this particular week for purchases made onboard'."
Were all of the items in question all manufactured in the EU? If so, are you aware of the concept of "EU Returned Goods Relief"? This only covers unmodified EU manufactured goods. The Tiffany & Co. item was quite possibly not EU production, and for that reason, Customs would have good reason to assume it to be dutiable. You would have needed to document the country of manufacture (somewhere in the EU) to avoid scrutiny, and that document should have accompanied your purchase onboard if this were the case.