I've said this in a bunch of different threads already, so I don't know why I'm saying it here, but...
The trade was a win for both teams. At the time, Indiana had Paul George and Danny Granger as Skilled, long wings. Kawhi was not going to play major minutes there. In addition, the Kawhi Leonard we see on the Spurs is not the player who was drafted. The body shape and work ethic were there, and those haven't changed, but Kawhi is much more capable as an offensive weapon because his shooting has changed from liability to asset. That changed might have happened in Indy as well, but it's not certain.
George Hill is also, a good PG. He's not explosive offensively, and he's never going to be an allstar. But he provides tremendous value as a medium usage, efficient PG. By WS48, He's at .177 This year. By PER, 16.59. The Talkingpractice guys(Adjusted +/- Group of statheads) Have him as 27th in the league.
No individual advanced stat is perfect, but the logical conclusion is that George Hill is an above average PG. For this, they gave up the 15th and 42nd picks(And Lorbek) in the draft, spots that usually yield Journeymen. That is the essence of the trade from their perspective. That is a win. There were also not a lot of Guard options in that draft. Nolan Smith might've been next up, and he's not exactly an NBA level Guard.
The Spurs were interested in trading for Kawhi. If he was gone, they probably hang onto Hill(Might've also targeted Jonas, but they were interested in trading if their guy was there, not a pick in general.) Kawhi was probably worth the 5th/6th pick at the time(combo of pre draft rankings from DX/ESPN & stat focused evaluation(Glowing)) and it is easy to see him having more value to the Spurs than Hill. We're all pretty comfortable with it being a good trade from our perspective.
It's bad that Bird won Exec of the year for it, as Buford's was better. But it was still a good deal, when you realise what options they faced.