Thankfully, they have ways of verifying historical facts so this [getting facts wrong] doesn't happen too much. One of them is Bayes' Theorem, which uses mathematical formulas to determine the probability that an event actually occurred. Ironically, the method is even useful in the case of Bayes' Theorem itself. While most people attribute it to Thomas Bayes (1701 - 1761), there are a significant number who claim it was discovered independently of Bayes - and some time before him - by a Nicholas Saunderson. This gives researchers the unique opportunity to use Bayes' Theorem to determine who came up with Bayes' Theorem. I love science.

John Cadley, Funny You Should Say That - Toastmaster magazine