DALLAS — Andrew Bynum swiped an errant pass intended for Dirk Nowitzki of the Dallas Mavericks, dribbled the length of the court and dunked late in the first half of Game 3 tonight. It propelled the Lakers to a modest lead by halftime. Bynum scored a team-leading 14 points on 6-for-10 shooting and grabbed four rebounds. Lamar Odom, starting in place of the suspended Ron Artest, had 10 points on 5-for-9 shooting. Dirk Nowitzki had 18 for Dallas. All in all, the Lakers did not look like a team bent on an early vacation. Then again, crumbled mightily in the second half of each of the first two games.