No, sued for actively recruiting them while still employed by the same company. He had a contractual duty of obligation to work in the company's best interest and instead spent dozens and dozens of hours on the phone with his co-founders and recruiting coworkers to leave with him.

I have no idea who is right or wrong legally here. That said, the complaint is clearly that he made job offers to current colleagues. Maybe that's untrue, I don't know. But it's much different than having already left the company imho.

Depends on the state. I think that flies in Texas of you've signed a non-solicit for instance.

This is a standard employment contract term. I don't agree with it, but in most of the US, if you signed a non-solicit, you cannot legally make a job offer to an ex-colleague. Even in CA, the state that most heavily policies anti-competitive behavior like this, they have not been entirely voided (although it looks like the law is headed that direction).