Only just joining in on this thread, but the hacking can be very much true, so I fully imagine his messages were being listened to.
I know someone who accepted a payout from the Mirror Group because of the phone hacking. Again, he could never prove for definite but there was overwhelming evidence.
In his case, he worked very closely with a singer who was known for being rather unstable and troubled.
Separately, his child was struggling with addiction issues and he had got them a place at The Priory.
The Priory called him one day and he didn't answer the call. The Priory went on record stating that they left a voicemail, but wouldn't have used the name of the patient, more of a "Hello Mr X, this is Doctor Y calling from The Priory. Could you please give me a call back?"
Within a couple of days there was a report in the paper that "sources" had declared the singer to be receiving treatment in The Priory.
It won't have been difficult for people to get hold of PH's mobile phone number and how many of us knew we had a PIN, or should change a PIN for our voicemails?
Of course, if CD could give evidence too backing up PH's comments, this would be all the more compelling.