Jerry West's 70 ft shot at the buzzer to send the game into overtime should not have counted. Wanna know why?

Don't get me wrong...I'm not hating on him. I would never criticize him since he is the official logo of the NBA. My reason for saying this is (and if you watch the highlights you'll agree) because when Wilt Chamberlain inbounded the ball to Jerry West he had one foot out of bounds and the other foot inbounds. That should've been a violation on Wilt. It was a HELL OF A SHOT by West because there was only 3 seconds on the clock. After the made basket Wilt grabbed the ball, stepped out of bounds with one foot while the other was still inbounds, and ped the ball inbounds. Both feet have to be established out of bounds first. Watch the highlight if you get a chance and respond accordingly. Tell me if I'm wrong or not. Not that it matters because it's still one of the greatest shots ever. But I need a witness to this violation.