This wasn't a typo. One person makes a typo. When creating a high-profile physical thing with text on it, there are authors, editors, typesetters (or the digital equivalent), copy editors, and proofreaders involved. If this wasn't reviewed by at least four people prior to printing, and if there weren't then test printings reviewed by additional people, then the entire process is flawed. But it still wasn't a typo. It was a failure in quality control.
My dig about education level was too subtle, so I'll be more blunt: too many stupid people were involved. People who don't know how to spell (barring special circumstances like dyslexia or communicating in a non-native language) are stupid. Everyone makes mistakes, but when multiple people whose job it is to produce something like this fail, it's no longer a mistake. It's because they were unable to review it and notice the problem.
All it takes is five minutes of reviewing Facebook posts or comment forums to see just how pervasive this stupidity is. Hacker News is one of the few forums I participate in, because most of the people participating are intelligent, and reading comments here doesn't make my eyes bleed.
As the sibling commenter stated, no one died, and this isn't a big deal. It's still an embarrassment.