the rear axle could have bent at the flange  or the housing bent  or both
jack that tire up and rotate the tire carefully watching to see if it has wobble,  if so  its the axle  if not its the housing,  check the housing with a straight edge

This happened to my truck, rear end came around on a slippery road and I slammed into a curb, D'oh!  The axle shaft bent, not the housing, causing the wheel to visibly wobble.  It vibrated at highway speeds and under braking, but I didn't leave it on long enough to notice a wear pattern, and I left it on for a week or 2 (couple hundred miles).  I don't think a wobble would cause the tire to wear heavy in just one spot, though, since the tire would be constantly changing it's toe angle.  To wear heavy in one spot the tire would have to have like a constant toe in or something.  I would guess the housing is bent.