I thought OJ was a bit risky tbh, to me it seemed like Jim was looking to the future for more of a puck moving d (as we can see now how much that matters in this playoffs) vs a more traditional high scoring guy like Sergachev. Or bypassing Tkatpuk, that was a bold move.
But I do hear what you're saying, if you never go for high ceiling you're never going to get it. At the time Petey looked like a reach down - only 1 of the scouting blogs had Petey at 5 !! most had him around 9 or even some around 20. (http://www.mynhldraft.com/2017-draft/2017-nhl-draft-rankings)