There is a distinction between a “pardon” and “clemency”. Clemency sometimes includes a “pardon” because its a general term but sometimes it doesn’t.
What Generals Diya, Olanrewaju, Adisa and others were granted in 1999 was clemency and not a pardon. It is now up to the Presidency to tell us whether the clemency that was given to these gentlemen in 1999 included a pardon or did not include a pardon. If it did then they have no business granting another pardon for the same people 13 years later. If it did not then they have every right to do so. This is my position.