"Can't be trusted" to express an opinion on the origin?

I was not initially going to write about this gold pot seized by German customs. Nathan Elkins has covered it quite well here and here (and clarified what was to me initially a somewhat unclear account in the Frankfurter Allgemeine Zeitung). However following on from this, an opinion has been expressed which deserves comment). Its from the Washington lawyer again, the one with an apparent irrational but pathological hatred of anything with a name that begins with the letters "archaeolo...". In his text "Recalcitrant archaeologist embarrasses German Police", Cultural Property Observer writes:

"Muller-Karpe is certainly well-known in Germany for his anti-collector and anti-trade views. Thus, it is a bit surprising German customs ever viewed him as someone who could be trusted to provide an independent opinion on the origin of
the vessel in question".

Regardless of the actual circumstances here, what a bizarre statement to make. I wonder to whom Mr Tompa would have had it taken by the German authorities. The Munich (coin) dealer Münzhandlung Hirsch Nachfolger which was trying to sell it claims it is from Iron Age Troy (but presumably, since this case is dragging on has not been able to document that). The attempted sale was challenged in 2005 and the object seized by customs on the grounds that the object was of a type suggesting it was in fact from Sumerian Ur. Michael Müller-Karpe at the Römisch-Germanische Zentralmuseum in Mainz is a specialist in the metalwork of the region, and the co-author of a 1993 work: Metallgefässe im Iraq I (Von den Anfängen bis zur Akkad-Zeit), Prähistorische Bronzefunde, Abteilung II, Band 14. So I'd say he was a suitable person to express an informed opinion on the origin of the object. In the same way US customs officers call on coin dealers such as Wayne Sayles to give expert opinions on numismatic objects stopped at the border.

Why should an archaeologist who is clearly a competent specialist in Near Eastern archaeology not be "trusted" to give an independent opinion on the origin of the vessel in question? Why should we "trust" an antiquity dealer any more?