The information regarding the Dolby issue came from Bernie Grundman, Chad Kassem, and Michael Fremer. Fremer posted a video on his Analog Corner website telling the story, which was subsequently further discussed with Grundman in another video.
I couldn't find the video, but I did find this:
“Both albums [Jakon and Tillerman] were recorded onto 3M or Studer machines on 16-track two-inch tape at 15 inches per second,” Samwell-Smith explained in the liner notes to the 2008 2CD “Deluxe” edition of Tillerman, “with Dolby noise reduction and mixed onto quarter-inch tape at 15 IPS with Dolby [noise reduction]. “ According to Sound on Sound’s Joe Matera, Samwell-Smith “played with the Dolby system during mastering to add compression and treble to the entire mix.” (Exactly how he did this isn’t clear, though producer/engineer André Perry has speculated that Samwell-Smith didn’t decode the Dolby noise reduction in order to create “a very present, dynamic, bright sound.”)
I also found this:
“The tapes are in still excellent condition, the Dolby A encoded BASF tape used has held up very well compared with other formulations used in the mid 70’s and later. The tapes sound excellent. I’ve done no limiting or compression on these files at all. Playback was done on an Ampex ATR100, and the A/D converter was a prototype MSB unit that David Chesky was good enough to loan us.” — Ted Jensen, Sterling Sound
Perhaps the truth here is lost to time.