Bara repeated what he had said during a brief spot on Coast to Coast AM, and on this he is perfectly correct (in content if not exactly in grammar):
The Daily Mail as well as other news sources citing this story have unfortunately mischaracterized the content of the memos. They have been presented it as if Kennedy was asking about UFO’s – or “unknowns” as he called them—and implying that alone may have gotten him killed. In fact, it’s clear from the memos that Kennedy already was well briefed on the “unknowns,” at least enough to know that there were “high threat cases” which needed to be included in the information sharing with the Soviets.
It's in extending that idea to a motive for assassination that he let his imagination run away. He continues:
What we have argued, and which now seems validated, is that it was the putting into motion of his plan to share not only our technology, but what would be discovered on the Moon that got him killed. If the Moon actually held the secrets of a long dead and highly advanced civilization, then protecting those secrets from a nation that most perceived to be our arch enemy would have been justification enough to kill Kennedy 10 days later in Dallas.
So, let's see... this plot was hatched and Lee Harvey Oswald was recruited and trained in 10 days?
Slight problem, here... Oswald started work at the Book Depository on 16th October, nearly a month earlier. Oops...
Of course, there's also the problem that there's no such thing as "the secrets of a long dead and highly advanced civilization" on the Moon. But nobody's going to convince Mike or his former co-author of that. It's their cash cow.