NEW YORK ( TheStreet) -- To a lot of writers, JPMorgan Chase CEO Jamie Dimon has been a rock star. To me, he's always seemed more like a very proficient plumber.I don't mean that in a bad way. Plumbers can be useful technicians when you need an expert who knows how keep the toilet from backing up. Dimon made his way to the top, in part, because he was a guy who did his homework, crunched the numbers, and made it his business to understand, well, the pipes and connections inside a securities firm. Now he's got a $2 billion problem that's making me wonder if he's even all that good at the detail work that's made him Wall Street's most-cooed-over magazine cover boy. That glitch would be the $2 billion loss announced Thursday, when the world learned that a JPMorgan hedging strategy had gone haywire, the result, in Dimon's words, of "errors, sloppiness and bad judgment" by his underlings. It was a whiplash-inducing turnaround from what he'd said only a month before. On April 13, when questioned during a quarterly conference call about reports of a JPMorgan "whale" who had made large credit-default swap bets, Dimon sniffed that it was all "a tempest in a teapot." We could easily forgive Dimon and his firm for messing up in an area that so many others have messed up in before, if only Dimon hadn't made it his business to be Wall Street's noisiest critic of the Volcker Rule section of the Dodd-Frank Wall Street Reform and Consumer Protection Act. Dimon told Fox News in February that Paul Volcker, namesake of the rule that seeks to rein in speculative investments by banks, is a guy who -- ahem -- doesn't understand capital markets. And he poked fun at the Volcker proposal for its discussion of whether a bank trader's "intent" was to do risky proprietary trading or market making, which Volcker allows. Under the rule, "we have to have a lawyer, a compliance officer, a doctor to see what their testosterone levels are, and a shrink," he said.