The Suns come out with a pretty standard inbound set up with the point guard standing below a big man on the ball side. Most side out of bounds plays feature the guard taking a down screen from the big man and popping to the top of the key. The big is in the post/elbow area as a safety valve (and sometimes even the first option).
As explained earlier, Luis Scola sets a down screen and the guard is opened up at the top.
He receives the ball at the top and everything seems fine. The defense is in position and there aren't any mismatches.
The ball is swung twice and eventually ends up on the near wing. On the far side, Scola is setting a screen for the inbounder who is cutting towards the lane. You see David Lee helping out. The initial receiver of the ball also cuts toward Scola after swinging it.
The initial ball handler now sets a screen for Scola whose man is already helping out. The usually effective screen the screener. Now David Lee is trapped and has to pick his poison. Does he leave the man he's helping on and allow an easy layup or stay put and allow an open 18 footer (money for Scola). He actually makes the right decision. Jarret Jack, defending the screener, needs to help out on Scola. He doesn't (and actually isn't even close) which shows either inexperience in Mark Jackson's system or lack of communication from his teammates. Either way, the fact that such a wide open shot can be attained by a simple out of bounds play should be disturbing for all Warriors fans. Hopefully strides can be made as a team defense this year and Bogut's communication will certainly help, but until the big Aussie comes back there will certainly be some stupid mistakes like this.