I hadn't heard of Halvar Flake but evidently he's a well respected figure in security - https://ringzer0.training/advisory-board-thomas-dullien-halv... mentions "After working at Google Project Zero, he cofounded startup optimyze, which was acquired by Elastic Security in 2021"

His co-founder on optimyze was Sean Heelan, the author of the OP.

Yes, Halvar Flake is pretty well respected in exploit dev circles.