But a moment later, watching the replay on the Jumbo-Tron, you see the receiver's left foot land on the white stripe. The referee was right - the receiver was out of bounds when he came down with the ball. 

Unfortunately, in trial, we never get the benefits of an instant replay.  To best tell our witness's story, we need to show why they have the ability to see, hear, or know the things they're testifying about.  If you were telling this same story to the jury, you wouldn't start by having the referee describe what he saw to the jury.  You'd start by showing that the referee was in the best position and had the best ability to see what happened.  Here are some of the things you'd want to establish before he told the jury about the catch:

By highlighting his ability to observe before asking him what he saw, the jury can place greater weight on his testimony.  In your case, consider the strength of your witness's vantage point.  Does the witness have any special skills that helped them view, remember, or interpret the event?  Does the witness have any special training, perceptive skills, knowledge, experience, or unique skills that allow them to see these events better than the ordinary person?  If so, teach the jury about those skills before you ask him what he saw.