Along with the previous quote, the same person gave me a link to the following embedded video:
In basketball (as well as some other similar sports like football and hockey), the offense tends to stall at the end of quarter (or period in the case of hockey) in order to prevent the other team from having a chance to score. In this game (that was played on Dec. 5th, 2009), Jarrett Jack of the Toronto Raptors is doing just that - stalling at the end of the quarter so that the Chicago Bulls will not have a chance to score. I will admit though that it is unusual to tie one's shoe while stalling. I could argue that it was actually a good use of stall-time.
Now you might wonder why Jack's defender, Luol Deng, did not try to steal the ball. The astute observer will realize that this is not an option. When the video begins, we have already missed a crucial event that would have helped to explain what was going on here. The Rapstors have the Bulls in a mismatch. Deng is not the proper defender for Jack; Deng is a 6' 9'', 220 lb forward while Jack is a 6' 3'', 197 lb guard.
At the 4 second mark of the video, Jannero Pargo of the Chicago Bulls motions to Deng that they should switch who they are guarding. Pargo is a 6' 1'', 185 lb guard but is guarding Marco Belinelli of the Raptors who is a 6' 5'', 200 lb guard. Althogh Benlinelli is a guard, the best defending situation is if Deng were guarding Benlinelli and Pargo were guarding Jack. However, in the next second of the video, Pargo changes his mind and motions to Deng to continue guarding Jack.
If Deng tried to approach Jack in an attempt to steal the ball, Jack would be able to make a move and get past him. At this point, the the Raptors would have a 5-4 situation and probably be able to hit a wide open three-point shot.
In conclusion, the events that transpired at the end of the third quarter of this game may have been unusual, but they were also the optimal strategy.
While not directly related to this situation (as I laid out above), Derek Gatheright presented an argument (in the fourth comment) as to when other situations like this could happen:
"That’s just good sportsmanship. It’s like in soccer when a player is injured and the other team has the ball, it is usually kicked out of bounds. It’s bad sportsmanship to take advantage of a situation like that."