I'm a little skeptical of this claim. When I've experienced sleep paralysis I've imagined seeing a non-supernatural human intruder but all I actually saw was a vaguely human shaped shadow which for some reason in the confused half-asleep state of sleep paralysis seems highly likely to be an ill-intentioned intruder rather than a shadow. People with a different cultural expectation might claim to have 'seen' a demon but I don't think that should necessarily be interpreted as them having had a detailed hallucination, just that an ambiguous and threatening presence is assumed to be whatever strikes them as the most likely thing to be hanging around threateningly if indistinctly.