You generally cannot know because we don't measure for it? Especially not on personal computers, maybe ECC ram reports this information in some way?
In practice I think it happens often enough, and I remember a blackhat conference talk from around a decade ago where the hacker squatted typoed variants of the domain of a popular facebook game, and caught requests from real end users. Basing his attack on the random chance of bitflips during dns lookups.
