Did he call Crimewatch when they appealed? We only have the friend's word for it. Possibly he did but might have been someone who looked similar fly tipping.Didn't the canal guy go straight to the police at the time. He went to Cannan's trial to see if it was him that he had seen dumping the suitcase. I believe he went three times to the police but they didn't take him seriously. It was a friend of his that then contacted police many years later and when they looked into it they didn't find any report about it.
If it was John Cannan he saw, it meant that he'd spent the last six nights in London (until the Thursday) yet he apparently turned up on Monday teatime at his childhood home in Sutton Coldfield with all his possessions and lots of bags in the hostel cook's car who I think drove him back.