I think OP was referring to Gary Linscott who has made major contributions to both Stockfish and made an adaptation of Leela Zero to Chess, now living under the Leela Chess Zero Github org but apparently a different adaptation is now the officially sanctioned one, at least his commits don't show up in the new lc0 repo.

https://github.com/official-stockfish/Stockfish/graphs/contr...

https://github.com/LeelaChessZero/lczero/graphs/contributors