Okay, I found this from 1999:
Halloween has been fully restored under the supervision of Lucasfilm's THX Digital Mastering Services. The video was transferred by award-winning colorist Adam Adams from a new 35mm inter positive (mode (sic) from the original camera negative) and approved by the film's cinematographer Dean Cundey.
That implies that Dean Cundey approved Adam Adams' work. It does NOT suggest that Cundey supervised the actual process.
Conversely, for the 35th Anniversary Blu-ray release, I found this:
Trancas International Films, Compass International Pictures and Halloweenmovies.com are proud to announce award winning cinematographer Dean Cundey is supervising the new high definition transfer of John Carpenter's Halloween for the upcoming 35th Anniversary Blu-ray
"Supervising" implies much more involvement versus just "approving."
I don't know how deep Cundey's involvement was with the THX DVD release, but it is pretty apparent he was quite
involved with this new Blu-ray release! And he said just that in the interview I linked earlier!
Adding it all up, my mind is convinced... Adam Adams at THX made these dramatic changes to the color timing on the 1999 THX DVD and those changes were run by Cundey for his approval. Basically, he simply signed off on the release. Period. It's my belief that, in that recent interview, when Cundey referred to previous iterations on DVD getting the transfer wrong, he was referring to the THX DVD as one of those examples. With or without his approval, he knows it was wrong. Likewise, the new Blu-ray is the first time it's been done right!