See now while I love this play I don't find that exchange notable. It's very plain, no? The implication is that one thought the other was going to say something but he wasn't. This exact dialogue takes place in real life regularly.

The alternative reading, where an entire exchange cleverly takes place without any substance, seems almost mistaken to me? In context it seems very clear it's "I thought you...[were going to say something.]" "No." "Ah."