Not sure how true this is but I heard it related to a drowning of someone close to him (possibly a family member) and the life guard did nothing to help. Phil then sent said life guard an invitation to one of his concerts where he played that song for the first time. The life guard knew what he was getting at in his lyrics and ended up committing suicide that night.
I believe what I was told though I don't have anything other than my friends word to back it it up so I won't tell you that this is definitely true.
"we'll if you told me you were drowning, I wouldn't lend a hand
ive seen your face before my friend, but I don't know if you know who I am
well I was there and I saw what you did, I saw it with my own two eyes
so you can wipe off that grin, I know where you've been
its all been a pack of lies"