It was funny for sure. But I didn't hear him say, "I'm done!" while he was still ahead. Somewhat reminiscent of what Gaston Gaudio said in 2005 when he was defending his RG title.
"Don't worry. You'll win today," he told Ferrer's coach, sitting in the stands. For Gaudio, the words proved painfully prophetic. He blew a 4-0 lead in the final set and lost.
Anyway, anytime your state of mind is reminiscent of Gaudio, that's not good.