That's a diversionary hypothetical, and not a very effective one. Especially given the obvious reality that Khashoggi's employer was the Washington Post, which clearly had a reason call out for the truth about his disappearance and murder, and the means to distribute that call on it's opinion pages.

Furthermore, the previous President addressed his killing in the mildest possible terms, claiming (laughably) that the Saudi ruler had no involvement.

https://mobile.twitter.com/Acosta/status/1064939271113637890...