Not only is it easy to make there is no downside to making it. If the markets don't turn down then, he can claim that they will in a couple more years, or the fed is juicing the stats, or something else.

What would be more compelling would be a screen shot of his portfolio that shows that he is much more invested in short positions than longs, or has moved his investment into something besides equity markets.

What would be downright highly profitable for him, is if he could show over a long series of years that his ability to "imagine" future market conditions outperformed a strategy of just buying the market over the highs and lows and averaging the return.