There's a presumption that NAS stores more-important-than-average data, so an error is a bigger deal. Also NAS systems often have check-summing and redundancy

There's a presumption that NAS stores more-important-than-average data, so an error is a bigger deal. Also NAS systems often have check-summing and redundancy on the disk, but if an error happened in RAM, then that error will be propagated into the checksum and redundant copies.