Thieves and charlatans can do far more than $20,000 damage to this platform.
Any time there's money involved, there are going to be liars.
If your friend is on the level, then ignore it or by all means defend the accusations with facts; but if we don't call attention to potential fraud when we see it, we'll be overrun in a heartbeat.
I realise it's a bitter pill, at a terrible time, but it's not personal.
My sympathies to your friend.