He didn’t have to hear it. Just the part about Cooper being willing to do anything for a fellow stockroom manager. His looking over at the very thing Ron needed and then saying he didn’t have any would have told Donnie that was what he had asked for.
How did Donnie hear Ron? It doesn’t appear that Cooper was using the speakerphone.
He didn’t, but Cooper’s half of the conversation covered it all.
Oh. Whoops. My bad.
The part about 16-inch shelves, though. How did Donnie hear THAT?
He didn’t have to hear it. Just the part about Cooper being willing to do anything for a fellow stockroom manager. His looking over at the very thing Ron needed and then saying he didn’t have any would have told Donnie that was what he had asked for.