There isn't much there.
Basically the site is "accusing" Martin of being instrumental in the Second Vatican Council's promulgation of Nostra Aetate, specifically the language in the document that clarifies the Church's theological perspective on Judaism.
This implies that the accuser dissents from Nostra Aetate - he is basically accusing Martin of being a "double agent" for Jewish interests.
And what has he discovered? That Martin wrote a book and magazine articles with a positive spin on Judaism and that either he or an associate were paid for their writing and that they put their wages in a tax-advantaged Swiss account.
How does that make Martin a "double agent"?
This isn't espionage - this is advocacy.
I'd like to know what the author's views on Israel and Judaism are if he has a problem with Nostra Aetate.
It should also be pointed out that NA went through a number of drafts and was worked on by dozens of theologians before being proposed to hundreds of bishops.
One English language book and a couple of articles were not the deciding factor.