Wanna bet the t-shirt writer went to U of Michigan?

It's been a long stretch without a post...but I can't resist sharing this article (FYI, Michigan is Ohio State's big football rival, so the title of my post is for all the Buckeye fans out there):
http://shine.yahoo.com/event/fallfashion/grammar-fail-on-old-navys-college-t-shirts-uh-oh-2531551/

On a side note, considering her choice of subject, I am going to choose to believe that the author is either British or chooses to write in the British style--because if not, she has a grammar fail in her article, too. Can you spot it?

"Hundreds of thousands of shirts...have been shipped to stores with the phrase 'Let's Go', sans apostrophe."