3 feet?? Oklahoma vs Kansaa

[rockchalk jhawk]

So when I saw this: Controversy brewing over final Oklahoma inbounds play - ESPN Video I came straight here to ask the rules gurus...

And before this thread goes off on another tangent, lets ignore the fact that Mason was probably breaking the throw-in plane. Not contesting that.

Where in the rules book does it say that Mason has to give Hield three feet in that situation?

And ignore my screen name. I'm a referee first and a fan second.