No, you wouldn't have to believe any of these things, if you believe:
-That Olshey was given the job and told who the scouting department liked, but was given the latitude to make any pick he wanted
-That Olshey agreed with the scouting department's take
-That whether or not Olshey wanted to draft Dame was not a condition of his hire
-That, 9 years later, Olshey properly values Dame as a franchise cornerstone and all-NBA player, and also the asset which would garner by far the largest and possibly even most lopsided return were it to be dealt
-That Olshey specifically values CJ as a superlative find in a crappy draft, much more than other picks he's made since
All of those things are perfectly reasonable, and jibe completely with the idea that Olshey might have more personal pride in CJ's selection than Dame's, and thus a greater emotional satisfaction in his success.