From what I understand of VCRs the S-Video output is only active for S-VHS tapes. Unless their recorder used those tapes it wouldn’t have been an advantage - or even work at all.
What he did do was use the 3 FBAS connectors for Stereo Audio and Composite video. Still subtle issues can crop up because analogue video is hard.
S-Video output on SVHC players is active for both VHS and S-VHS tapes. VHS (normal) signal is not exactly the same as composite, the Y and C signals are encoded differently, meaning there _can_ be a benefit from only decoding VHS and not re-encoding into composite.
What he did do was use the 3 FBAS connectors for Stereo Audio and Composite video. Still subtle issues can crop up because analogue video is hard.