"True worries are fine;
sell if you see new cracks, but
you're doing it all wrong."
-- Anders Bylund, 2010

Of all the reasons for a sell-off I've ever seen, this has to be one of the worst.

Harman International Industries (NYSE: HAR) just reported a mighty fine third quarter of 2010 (remember the year!) with 42% year-over-year sales growth and drastically better earnings. Revenue now stands at $848 million in the third quarter, while last year's $0.93 non-GAAP loss per share turned around to $0.31 of income per share.

The $400 million cost savings program is running ahead of schedule, Harman is in active talks to introduce its high-end audio and video systems in several major car brands, and the company just kicked off a branding campaign that should raise consumer awareness of Harman's many product brands, from Harman Kardon and JBL to Infinity and DigiTech. The company is selling off non-core operations, like when it unloaded the QNX software division to Research In Motion (Nasdaq: RIMM) earlier this quarter.

All of this is great news that should be pushing Harman's stock higher today. But the share price is down over 20%, and Harman has the dubious honor of being the second-worst performer of the entire stock market today.

So what gives? Well, Harman did issue forward guidance, too. In 2013, Harman expects to report full-year earnings of $3 to $4 per share after growing sales by 7% to 10% per annum. Automotive sales will lead the top-line charge, while there appear to be some costs left to squeeze out of the professional audio/video products division.

Yeah, that goal post stands three years away. To punish Harman for modest or conservative revenue growth guidance on this scale is like firing your quarterback for missing a Hail Mary he hasn't even thrown yet; and the guidance really isn't terribly pessimistic.

If Harman did anything wrong today, it would be hauling out a dusty crystal ball that investors apparently weren't ready to see yet. At least Harman's skeptics didn't drag the entire consumer electronics sector through the mud for one company's perceived sins -- Apple is up today, and so are Sony (NYSE: SNE), Philips (NYSE: PHG), and Panasonic (NYSE: PC).

Is this a monumental misinterpretation of Harman's way-too-early guidance, or should we really worry about a company that appears to be in fine form? Share your insights in the comments below, please.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. National Poetry Month sings a sweet, sweet siren song in his ear every year. Apple is a Motley Fool Stock Advisor pick. Try any of our Foolish newsletters today, free for 30 days. You can check out Anders' holdings and a concise bio if you like, and The Motley Fool is investors writing for investors.