It has come out more recently (2019) that Sally Ride was putting him on the trail. He acted the irascible dogged investigating scientist, and she got the astronauts' worries about shuttle program specifics out to the public.
To add to what others said, I believe his biggest contribution to the Challenger investigation (beyond his insight and damning conclusions) was that he refused to censor himself and his report for political or public-relations reasons. IIRC he said if he weren't allowed to publish his part of the report in the way he wanted, the commission was to remove his name from the report entirely, because he didn't want to be associated with a report that pulled punches.
He was involved in the investigation committee, but of course wasn't the only one there. IIRC Neil Armstrong was also on the committee. I figure that part of the point of choosing them was to lend the committee credibility with the public. The public would probably trust that the findings were above board if they were supported by the first man on the Moon and one of the most prominent physicists of the time.
