09 had just enough room to pull to the inside of the 99.

https://www.youtube.com/watch?v=sRBJxRpEitw

Check out this angle of the wreck at 3:54 and 4:19. The 99 tried to go up to block so the 09 went to the bottom. The 09 already had his bumper inside and had a run going. Pay attention to the "lane markings" on the track. The 99 clearly came down and did not hold his line. In NASCAR, if you do not hold your line, especially on the last lap, you will get spun. In other motorsports, maybe not. If this was F1 or a touring car series, I would agree that the 09 could get a black flag, but this is NASCAR.