> Confirming Mr. Barnes’s account is problematic after so much time. Mr. Connally, Mr. Casey and other central figures have long since died and Mr. Barnes has no diaries or memos to corroborate his account. But he has no obvious reason to make up the story and indeed expressed trepidation at going public because of the reaction of fellow Democrats ...

> None of that establishes whether Mr. Reagan knew about the trip, nor could Mr. Barnes say that Mr. Casey directed Mr. Connally to take the journey. Likewise, he does not know if the message transmitted to multiple Middle Eastern leaders got to the Iranians, much less whether it influenced their decision making.

"Historical fact" is a very strong way to say "one man's story recounted 40 years later and backed by modest circumstantial evidence", and even to the extent the story is true as told in that article, Reagan's backers didn't "conspire" with anyone—as recounted, they never spoke with the Iranians, they told other Arab leaders to let the Iranians know.

If true, this is still worth recounting, but you're not helping anything by overstating the degree to which we know this to be fact nor by overstating the crime.