There's no parity on CD Audio, unlike CD-ROM. Therefore, as the bits fly by, you cannot be sure that you read the disk absolutely correctly. (If you read the CD spec, it's a miracle that the bloody thing worked at all). Small errors may have been undetectable audibly but that didn't stop player manufacturers doing oversampling to get a better handle on what the bit value actually was.
The question at the time was whether the bits you burnt on CD-R were "sharper" than those on commercially manufactured CDs and therefore sounded better because a) less quantisation noise occured and/or b) less processing being done by the DACs.