Watch the whole play. After he got his **** stuffed (not a problem, as at least he tried to attack the rim), Favors scrambled to try to grab the offensive board. The Lakers secured it, and started running. Al jogged back, getting beat down court easily by McRoberts despite having a head start on him. This forced Hayward to help on McRoberts, leaving Artest open. Favors, having somehow beaten Al back on D, scrambled to get out on Artest, who pump faked and drove to the hole. Al secured poor position trying to box out Gasol, paying absolutely no attention to what was going on around him, forcing Hayward to try to help late. The dunk ensued.
This play was no surprise. Al is terrible running the floor and helping his teammates. His on-court awareness is ridiculously bad. His offensive performance (highly overrated on this board) doesn't come close to making up for these constant mistakes.