Somnambulism

I suspect that the most likely explanation is that your friend misremembered and that the sleepwalker in fact had his eyes open during his sojourns. It's not particularly unusual for sleepwalkers to engage in any number of activities while asleep, but with no recollection of the activities upon waking.

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Those who would sacrifice an essential liberty for a temporary security will lose both, and deserve neither. -- Benjamin FranklinWe see monsters where science shows us windmills. -- Phat