The top federal income tax bracket is 37% and the top California tax bracket is 12.2%. This is for income exceeding 500k. So disregarding local taxes and property taxes, in California most of this income would be taxed at 49.2%.
> That would require greater than 50% taxation, which isn’t realistic at all in the United States.
My point is that higher than 50% total taxation on a large single-year income (considering local and corporate taxes) is entirely possible in the United States, though it may be less in some states than other. I’m not saying that the estimate is correct as the Tarn Brothers don’t live in California. But if they took the income to a corporation, paid corporate income tax, and then took the whole income or a large part of it as dividends in a high tax state, then >50% is quite possible. On a pass-through entity, close to 50% is the standard and unavoidable in high tax states.