Luol was a OAD in an era where he was under no obligation to attend college. The mere fact that he arrived on campus despite being rated as the clear #2 player out of high school (behind only Lebron) was a pretty strong endorsement of his genuine desire to play here. The #1, 4, 5, and 14 guys in the RSCI rankings all declared right out of high school and were selected in the first round. If Luol really had no interested in college, he could have done the same. The option was there.
The fact that he cared / thought about the NBA makes him basically indistinguishable from the overwhelming majority of top-end kids we've had come through our program. Reality is that since J-Will, Duke players with top 5-10 draft stocks have basically all declared (with the possibly quibbling exception of McRoberts, who was arguably a late lottery pick). At the time, many of us were surprised when he declared. But, it turns out that he was just a lagging indicator at Duke of something that had been going on for years. And, I'd note that he declared in a year where we also suffered our first NBA defection from a signee (Livingston).