In the case of Thain, he signed off on these expensive corporate renovations after Merrill "won" the battle to get him as CEO (remember Citigroup ( C) wanted him too). At the time he took over the company a year ago, he was one of the kings of Corporate America. He might well have felt justified in green-lighting these expenses and using his own decorator. It's also interesting to note that, in all the criticism of how Ken Lewis of BofA failed to do sufficient due diligence on Merrill prior to announcing the deal, no one has criticized John Thain for insufficient due diligence on Merrill prior to taking the top job. At the time of his hiring, he assured the press that he'd been given complete access to Merrill's books. Apparently he did a poor review. When Merrill's fortunes started to go south, no one went back to ask Thain about this oversight. What this sorry episode teaches all analysts, media, and investors is that we need to appreciate success and achievement but always remain skeptical. We shouldn't be afraid to ask tough questions even about "untouchable" CEOs like Apple's ( AAPL) Steve Jobs, JPMorgan Chase's ( JPM)Jamie Dimon, or General Electric's ( GE) Jack Welch. Past success no longer guarantees future success in today's world. Unfortunately for BofA shareholders, no one had warning signs about Thain until the last 72 hours. (And let's not forget that, if you're a Merrill shareholder, you are overjoyed that Thain sold this company at such a premium and kept the fourth-quarter loss under wraps until the deal went through.) One thing's for sure: If you're a company insider and you hear about a big corporate office renovation, starting looking for work and start selling your insider stock right away. Neither Eric Jackson nor his fund own stock in Merrill or BofA.