I'm with Harrock on this - it's an interesting puzzle, sorting out the sources, and always food for thought, but the sparring of the two organizations is mostly marketing, as it's getting them press coverage for free, and fairly inconsequential in the scheme of things.
I also think that the question of "inspiration" is being confused - deliberately or not, I can't tell - with "referenced from".
Hergé could have been inspired
by all sorts of things - it could, for example have been a nightmare he himself had had, or he could have read some of the many tales of Egyptian mummies and curses, or seen the Universal horror films depicting the reanimated mummy, or just reading about the supposed curse of Tutankhamun, and then applied it, redressed for his South American tale, in his own book - the use of the dictionary or museum artifact only being for artistic reference, not inspiration as such.
I've pointed out before a pretty close analogue to the nightmare scene
to be found in the art of Edumnd Dulac; I reiterate that any link is entirely
speculation on my part, but I repeat it here as an example of the above point: that had Hergé seen this, and thought of it as a suitable basis for a vignette in his story, it could be this
that was the inspiration for the scene, and the mummy, and any use of the dictionary, or museum exhibit(s), would be purely for reference.