No, it was an agreement to NOT HIRE any employee
Look at The Verge post
It depends on who you're referring to. The Verge post did mention Pixar not hiring a guy, but that's unique and not the general agreement amongst the companies. (I'd venture a guess the guy in that HR dept just screwed up.)
All the other notes in the post refer to sacking the guy in HR who cold-called. (Personally, I'd think sacking the HR guy was kinda going overboard.)
sessamoid and Mal are correct in that the agreement was to not poach or cold-call. And that should an employee choose to apply themselves to a competitor, they're free to do so. (I've talked with people in Google's HR dept about it as well. My opinion was that I thought the whole thing made sense and wasn't unfair to the employees.)
In fact, the Verge specifically titles the post referring to it as a "no poach scandal". Not a "no hire scandal."