I wonder what OS he used, which CD-ROM drive was in the machine, and which ripper he used.
I have been ripping discs since the first ripper for Windows 3.1 became available. My own experience with that process has shown that the process is not so clear cut and accurate. A disc with many errors might play quite happily in a CD player, but would not rip properly. Then there are rippers that are more accurate than others. A CD player has the Reed-Solomon error correction built in, but I have never found any reference to that error correction process in any ripper software.
I would say that any disk drive will have error correction built in.
A CD player can happily skip frames if there are errors, it doesn't really matter. Thats why disc with errors can play in a CD player.
A PC can't afford to do that because it reads the CD as a storage medium, and ripping aims at making a perfect copy of the data.
I'm sure if you play your CD in a CD-ROM drive as a music cd (with some music software), a disc with errors would work as well.