Since June 2009, when that interview was conducted, the S&P500 has more than doubled, not including dividends, so I hope he switched back or he did, in a sense, "lose" 50%.
Numerous financial experts assert the current valuations within the stock market do not reflect the underlying fundamentals; or, in other words, ZIRP allows for cheap debt in the bond markets which many firms are using to aggressively buy back stock, thereby artificially inflating the market value. Thus, "a correction" is due and his statement is still valid from a conservative investing standpoint.
http://dqydj.net/sp-500-return-calculator/
Picking arbitrary dates to buy a lot of equities and then not selling them isn't market timing; trying to trade repeatedly on the right dates is. That's how you lose all your money.