I have been told by another Catholic that they are false, but I wish to make sure myself.
That's hardly a good reason to doubt them.
I have found many quotes about Jews are genuine.
I haven't read Judaism discovered but I imagine if you read it you will find the explanations.
I haven't met the person who told me online, but he says that he is a convert from Orthodox Judaism, so I presume that he is good willed and telling the truth.
Again, I have no doubts that many of the positions of Hoffman are correct, as they have been alleged also by many other Catholics but I want to read them myself from the Talmud.