I see you made the edit, but yes, Reeves guarded him for a while and has several inches on him. I'll say this, he only hit 2 open 3s. The other 8 were off-balance and a hand in his face. Or at least close enough to theoretically affect his shot. He was just unconscious. Not to mention fearless, which is what you have to be in that environment.
At the end of the day, UK only gave up 80 points, which seems like a lot, but for them, that's their average. And that kid scored 32 of them, so it's hard to say they lost because of their defense. It's almost exactly what they did to Tennessee in Knoxville. They gave Knecht his 40, but held the rest of the team to 41. Last night, they gave Jack G. his 32, but held the rest to 48. The rest shot 37%. UK just isn't going to win when Wagner, Sheppard, and Dillingham shoot a combined 3-19, share 8 rebounds, and 10 assists in 71 minutes.
Gohlke wasn't the primary threat for Oakland on the scouting report. Not even the secondary threat. You listed his limitations. He's an opportunistic shooter who just caught fire and became the primary offensive weapon. No one else shot over 50% for them. UK tried to adjust by running different defenders at him, even a taller one. He just shot over and around them. To your point, though, maybe they should have tried to put Ivisic put on him. Gohlke isn't driving around him and shooting over him would have been very difficult.