Ben Affleck apparently went as his pre-rehab self when he attended a Halloween event in L.A. on Saturday night. The 47-year-old actor was caught on camera appearing to drunkenly stumble outside the Unicef Masquerade Ball in West Hollywood, grabbing onto a parked car for balance. But by Sunday, he seemed in good spirits--and off the spirits--when a videographer caught up with him as he headed into ex-wife Jennifer Garner's house. "It happens. Just slipped, but I'm not gonna let it derail me," Affleck said. He didn't answer when the paparazzo asked him if he'd now go back to rehab.