These are the kind of classic "Spell checking. It's impotent!" type of situations. For long bits of text, I can see how somethings might slip through. When it's only 4 friggin words, and it's a campaign being slapped up on multiple billboards for everyone to see, one might think letting someone else review/approve would be a good idea. Thinking it might have actually done that and still nobody caught it is even more funny/sad.