Yeah he looks a little silly in hindsight, but when you're done you're done. I've always thought it's silly that tapping to avoid a broken arm is ok, but tapping to avoid concussion is a pussy move.
I even had this conversation with a local MMA fighter some time ago, he told me he'd been punched 53 times in a row on the ground (he was a pure striker). I asked if he thought about tapping and he said "fuck no, that's a bitch move". I'm not a fighter and was in a room of other fighters so didn't push the issue, but wanted to say it's fuckin dumb to not think you can tap in that situation.