Some other people in the space (non-technical people) thought it was weird that he wasn't more outspoken about his accomplishments, and they even went so far as to doubt that he was heavily involved.
As an introvert, to hear people dismiss someone on the basis of them not boasting about themselves really stuck with me. I just can't express how vulgar I find that viewpoint, and my opinion of the people who dismissed the guy has changed irrevocably.