What: Shares of BofI Holding (NASDAQ: BOFI) fell 15% today as the market showed its cool reception toward the company's post-earnings conference call.

So what: Investors knew BofI Holdings would handily crush earnings expectations for the third quarter, given that the bank's CEO, Greg Garrabrants, had indicated as such on a conference call little more than a week ago. That made last night's conference call the perfect forum for even more discussion about the allegations made by a former auditor, Matt Erhart, against the online bank.

Garrabrants used part of his prepared remarks to again deny claims made by Erhart. He then read a brief snippet of a letter sent to BofI by another former auditor, Jonathan Ball, which explained why he abruptly resigned from the bank in March.

Until last night, the public really only knew about Ball from an article in the New York Times. That report suggested Ball left BofI Holding at around the same time as Erhart because of "concerns about how the bank was responding to regulators," citing an unnamed source. Erhart has stated he left for a bevy of reasons, of which BofI's relationship with its regulators was one of the most integral.

Garrabrants read the letter on the call, which offered an alternative explanation: Ball left because of "burnout caused by continuously long hours," not because of the bank's relationship with regulators.

Score one for BofI Holding. There apparently aren't two whistleblowers, just one -- Erhart.

But what's likely spooking the market today isn't what Garrabrants said, but what he didn't say. After a brief monologue, Garrabrants opened the floor to Q&A by announcing that he wouldn't comment any further on Erhart, or take questions about the issue for the rest of the call.

Of course, analysts had other plans. In one noteworthy exchange, Robert Ramsey of FBR Capital Markets asked Garrabrants to confirm that he was not aware of any ongoing investigations by federal regulators at BofI Holding. Garrabrants declined to answer, referring him to "very clear statements" that he made on the two earlier conference calls. Ordinarily, when an executive chooses "no comment" or "see my last answer" over a simple "no," the market usually assumes the worst case scenario: BofI Holding may be under investigation.

Score one for the...well, not the BofI team.

Now what: If you like playing Sherlock Holmes, you'll love this story. Erhart has filed a complaint against BofI Holding; BofI fired back with its own complaint in federal court.

With a loyal group of bulls, an entrenched group of short sellers, accusations of fraud, and a lofty valuation, this stock simply has all the makings of a big daily mover. Until the truth is finally revealed, 10% daily moves could be the new normal.

Jordan Wathen has no position in any stocks mentioned. The Motley Fool owns shares of and recommends BofI Holding. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.