That's why I don't like +/-. Nelson being in the game had nada to do with Howard getting his 2nd foul and sitting in the 2nd, or Kobe getting hot and hitting everything. 2nd qtr is when LA took over, and Skip was back for the 3rd.
Nelson outplayed Rafer. That's pretty sad considering how long he's been out. It's possible that his return could have disrupted something with the rest of the team that isn't visible on the stat sheet, but individually he did much better than Alston out there.