Say what you want about the tech sector, but it's never boring. Any given week will keep tech investors flooded with product announcements, earnings surprises, and crazy strategy shifts that absolutely nobody saw coming.

These are three of the most shocking pieces of tech news this week.

1. No more telecommuting
When Marissa Mayer took the CEO job at Yahoo! (NASDAQ: YHOO), you could smell change in the air. So far, she's revamped the company's cell-phone policies, pushed out a redesigned front page for Yahoo!'s crucial portal site, and delivered a rare 2% year-over-year revenue boost in her first quarter on the job.

Mayer clearly brought some of her Google (GOOGL 0.55%) mojo over from her former employer. As a Google shareholder, I'm sad to see her go because Big G lost an incredible talent here. And injecting some Google funk into Yahoo! Is never a bad idea, as even a cursory glance at the two companies' stock charts will tell you:

YHOO Chart

YHOO data by YCharts

But this week, Mayer delivered a shocker. Yahoo! has long offered a generous telecommuting policy, placing more value on getting the job done than on doing it at the office. That's a thing of the past. From now on, Mayer expects her workers to make the daily commute in order to set up meetings, mingle by the watercooler, and generally break down barriers between different projects and ideas.

Creating synergies and happy accidents by forcing people into the office may or may not work. Only time will really tell. But the whole concept flies in the face of contemporary management philosophy. Silicon Valley neighbor Netflix (NFLX -3.92%), for example, wants to staff its halls with superstars and overachievers. It's done by demanding high performance from everyone, while mediocrity earns you "a generous severance package."

But you're free to work when you want, where you want, and how you want -- as long as the results are impeccable. Netflix doesn't have a vacation policy -- just take as much time off as you need, and then come back with fully charged batteries and get back to doing an amazing job.

Other companies have followed Netflix's lead. Data delivery expert Akamai Technologies (AKAM 0.42%) stole its vacation policy outright. Telecommuting is standard operating procedure in many Valley firms, and it's spreading to other industries as well. Mayer's policy change feels like a big step backwards. Let's see if she can prove me wrong with stronger innovation and better overall performance in the coming quarters and years.

2. Andrew Mason can joke about anything
Digital coupon wrangler Groupon (GRPN 0.57%) delivered another terrible quarter this week, after which founder and CEO Andrew Mason made a quick exit.

So far, so expected. Mason has long been a liability to the company he founded, and Groupon's rebate management operations never struck me as a great business plan anyway. But he did not go gentle into that good night. No, sir. He turned his exit into a stand-up comedy show.

"After four and a half intense and wonderful years as CEO of Groupon, I've decided that I'd like to spend more time with my family," he wrote in a farewell note to his staff. "Just kidding -- I was fired today."

He went on to explain that a lot of Groupon's horrific performance over the last two years can be laid at his feet. "As CEO, I am accountable."

Mason didn't exactly quit by his own choice, which would have given those parting words a special power. It's still refreshing to see an ousted executive go down with this much humor and dignity. Will Mason find another high-ranking job after failing so spectacularly at Groupon? I don't know, but this note gave him a fighting chance.

3. The Cook effect
Remember when Apple (AAPL 1.27%) CEO Steve Jobs told us that his latest gadget was pure magic -- and nobody doubted him?

Jobs made a sales meeting out of every speaking engagement. When Steve spoke, Apple shares jumped. Walk out on stage, make an elegant and persuasive presentation, leave the stage, reap the rewards. That's how you build an empire.

This week, current Apple CEO Tim Cook reminded us that it just doesn't work that way anymore.

Apple shares are off to a terrible start in 2013, falling 19% while the S&P 500 has gained 6.5% so far. Cook is under fire from investors, analysts, and media outlets. Some, like hedge fund manager David Einhorn, have concrete ideas on how Apple could treat its shareholders better. Others just raise questions in search of an answer.

This week's annual shareholder meeting gave Cook a stage to answer some of these questions, and to soothe the frayed nerves of his investors. Under Steve Jobs, the event would probably have smoothed over many of Apple's flaws like butter on the ragged top of a hand-split English muffin. But Cook fumbled the PR opportunity, buttered side down.

Just look at Apple's stock chart for this Wednesday and see if you can tell when Cook took the stage:

Source: Google Finance.

That's right -- the meeting started at noon Eastern time. A few minutes of voting and other pleasantries, and then Cook faced the audience around 12:30 PM. That's exactly where the chart takes a downward turn.

Cook was clearly on the defensive here, telling everyone that Apple's recent price performance hurts but that you should really focus on the long term. Sound advice for sure, but not what investors wanted to hear. Apple investors didn't leave that meeting inspired about a great future, as they probably would have if Steve Jobs had been available to emcee the show. Huffington Post confirmed that share prices often drop when Cook holds court at public events. PC Magazine sized the Cook Effect in a range between -0.9% and -3.6% per event.

Maybe Cupertino should get a more charismatic executive to run these presentations. Does Sir Jonathan Ive have any spare time on his knighted hands?