Yeah, a lot of places are still pretty strict about accepting only traditional fiat as proof of funds, even if crypto is legal. El Salvador is an exception since they've embraced Bitcoin, but most countries stick with traditional currencies. And Dubai too, I heard they can use it as proof.
I checked the UAE Visa Information on the Emerate website and the information that Dubai accepts cryptocurrencies as proof of funds is not available there. Dubai has been crypto friendly but they are not accepting it for the above purpose. Maybe you can share a link where you got the information.
one of the reason why we hold bitcoin some time for for such emergency and one good thing with bitcoin is that it always give you the opportunity to buy back at even a probably cheaper price, so instead of the dude to be sad about the whole thing he has taken the decision to liquate his asset to cover up for his traveling demand, most of the countries around the world probably prefer visitors prove of funds to be in local currency, some go as far as checking the banking history of the applicant.
Selling some part of his holding and presenting it in fiat would have been the easiest pathway. But we are all aware of how the market is now. Selling now is not a good move since the price of Bitcoin has dropped significantly. I don't think he would consider such an option.