he is saying that 'most terrorist money comes from charities' does not imply 'most charity money goes to terrorists'

I appreciate you are pointing out the logical fallacy. Thou I’ll point out that their money is laundered through is different from their money comes from.

yeah I debated trying to bring that up, but felt it would make the point a little more complex and he's still wrong even if the money wasn't laundered

"Most X's are also Y's" does not imply "Most Y's are also X's." We would need additional information about the X and Y populations to make this stronger claim.

However, making this claim incorrectly is one of the more common logical fallacies. Given that, it seems more appropriate to attribute the error to logical fallacy than to specific racist intent, again, unless we have more information about the authors with which to make this stronger claim.