So here's a theory, which at least makes this plausible:
Let's say that, for the purposes of Preseason All American selections, players at each position are evaluated in certain categories against all the other players at their position. Let's say that there are 1000 SG's total on the 384 D3 teams. We'll go way out on a limb and say that the top player in each ranked category gets 1000 points (for being the best out of 1000) and the worst gets one point. Let's say that there are 700 SG's total on the 276 D2 teams. The top ranked player in each category would get 700 points, and the lowest would get 1.
Prior to recruiting, O'Brion was considered by WIS to be a D3 player. Let's say that he is right around the 60th percentile as a D3 SG. He gets 600 points in, oh, 10 categories or whatever. That's 6000 points. That wouldn't be nearly good enough to get anywhere near the top of the leaderboard in D3. Now, a PERFECT D2 score would be 7000 points.
So here's the possible glitch. After evaluating him on the player level, as a D3 player, then WIS has to put the lists together. O'Brion has his 6000 points in his pocket already. WIS looks at all SG's on D3 teams and, well, wouldn't you know it, O'Brion isn't there! The D3 Preseason AA's come out as normal. Then, WIS looks at all the SG's on D2 teams, and, WOW, this guy has 6000 points attached to his name! He gets slotted in among the players that WIS always considered D2 players, who had a much smaller pool of points available to them. That 6000, instead of being at the 60th percentile, is suddenly 2nd highest of all SG's on D2 teams. Meet your new 2nd team SG.
It's a shot in the dark, but the logic works.