I'm 6'4" and having stood next to him there is no way he is 5 inches taller than me.
I couldn't find a great picture, but here's one where he's standing next to Talley and Conditt. Talley (who goes at 6'7") looks taller and Conditt definitely looks taller than than the inch difference between 6'9" and 6'10" which Conditt is listed at. I can't imagine the angle distorts things too much as they appear to be standing right next to each other. But in any event, a dumb thing to be arguing about.
I mean this all as a compliment. The kid plays his tail off and tries to get position. But at his height he should be guarding 4s not 5s and is just at a bit of a disadvantage there.