No, they were overrun after taking a shot, which compromised their position.
The incident you're talking about happened much earlier, in Iraq. I believe this article is referencing it: https://www.dvidshub.net/news/6921/former-magnificent-bastar...
It doesn't say they fell asleep, because of course there's no way to know that. It's an assumption that has been repeated as fact, though it does seem likely.
