I believe it was just one of the items the Ipsos left for him to play around with in the early stages of his testing. If I recall correctly, when Nelson came in to work on the terminal, he briefly picked up the ball and examined it before tossing it down and then spending the rest of the day working on the terminal. That part could have been subterfuge and it's possible he pulled a switch with the ball and left his message making one while he was there.
Did I catch that right?
CZ