That's the half of the transaction the grandparent comment didn't talk about. He was talking about the fact the customer in question paid using his Coinbase account so no crypto currency was technically moved as a result of that transaction.

...Not that I think it's a bad thing if a bunch of Bitcoin transactions (especially microtransactions) go off the blockchain, I just wanted to point out that off-blockchain transactions weren't inherent to accepting Bitcoin through Coinbase.