Well part of the answer is that we don't know. If we didn't see him do it, I can't tell you for sure that he can do it.
But there are lots of things we didn't see him attempt, or at least not with any kind of consistency or sustained focus. We didn't post him, we didn't put him as the ballhandler in the pick and roll, we didn't run him off screens to the middle or baseline for lobs, we didn't put him at the point of the press.
Now maybe that's because he isn't good at them or comfortable with them and Cal knew that wouldn't work. Maybe it's because for some of those things, another focus to another guy was a better option. If Hami's effectiveness at it is a 7 but SGA does it as a 9, you can't really run it for Hami. You can't run sets for all five guys at once unless you have the most perfect team ever assembled. Something has to give.
So if (according to Jerry Tipton's interpretation) Diallo feels like there are parts of his game he didn't show here, that's understandable.
We see it every year. Davis and Towns were better perimeter shooters than we let them be. Bam is better off the bounce and blocking shots than his role here displayed. Devin Booker has a better handle and is a better passer than we knew. Jamal Murray is basically a point guard.
But instead, it's eye rolls and sarcasm that maybe we haven't seen the full arsenal or best performance from a bunch of 19 year olds trying to figure it out in 6 months. It's no wonder our fans are horrified when guys go pro.