Fair enough - it's a great song in many ways, but that line just doesn't do it for me. And given its emphatic position at the end of the verse, I feel it neeeds to have more meaning, more of a genuine either/or.

But like I say, maybe Bob earns the right to leave it mysteriously vague. I still don't think it does the song any favours.

'Or just haunted by the loss' would work, for example.