That is a typically stupid comment.
Any RATIONAL and ethical person would not throw around serious accusations so cavalierly. Particularly when he has NO proof of anything.
We don’t have “proof” by your standard of 90% of what is written about here on FR.
A major figure in politics with demonstrably good sources (and a decades-long close relationship to Trump) became comfortable with his sourcing on it.
Surely that is good enough for posting here with the caveat that I offered. Moreover, it is fitting to the discussion, where the dynamics of Flynn and Flake are also involved.