I still find it weird that he has to pay taxes in dollars on something that he doesn't know the value of in dollars since he hasn't converted his cryptocurrency assets to fiat yet.
You can’t convert your real estate into stock without paying taxes anymore than you can one crypto coin to another.
Seems like people should have found better exchanges that would have helped facilitate tax reporting...
Not saying it affects the situation, but it is still a different type of transaction in the way that a lot of laypeople would think of it.
EDIT: even if he didn't convert to fiat, the exchange of BTC for an alt-coin is a taxable event. That makes sense because otherwise you could, in theory, convert to a dollar-pegged crypto like Tether and defer taxes indefinitely.