Illegal Procedure Penalty

[CVguy]

I listened to the broadcast of Robert Lee vs Irion County last night. One of the plays, Robert Lee completed a pass to the Center and scored a touchdown. The play was called back and Robert Lee penalized for an illegal catch. The broadcasters tried to get an explanation, but none was given. When did that become an illegal catch?

 

[Cline]

Kid stepped out of bounds before catching the ball, making him an illegal receiver.

 

[CVguy]

I wondered about that, but nothing was said by the announcers about him stepping out of bounds before he caught it.