Did you check the left cam in relation to that banks TDC?

I'm not sure how the variable cam timing works on this specific engine but, have a look at a M104 inline 6, it is probably similar. These have a helical spline system. There is a inside spline on the sprocket , a inside / outside spline piston and a outside spline on the cam side. When oil pressure enters ( or maybe leaves ) the area behind the piston, the ID / OD spline slides back and forth altering cam timing.