The "differential.allow-self-accept" option in Diffusion (default to false by the way) specifies if user can accept commit that he made.
It turns out however, that it has no effect and that user still sees "Accept Commit" in dropdown before comment textarea in the bottom of his own commit.
Even though option has "differential" in it's name, but it has affected the Diffusion commits being audited as well. Now it doesn't.