Coming upon that map of Jack's perambulations with a fresh eye, it strikes me that it could represent an individual simply wandering almost at random while thinking through a major problem or decision. If that decision was ultimately to leave home and cut contact with his family he could have hitched a ride out of the immediate area but asked the driver not to let on that he had done so.
I believe he was trying to hail a taxi, likely on uber or something. The phone call with his friend cutting out makes me think there was very little phone service in the area. My partner is from Bristol and has been in that area many times, he said that there is decent cell service there if you have a certain SIM card. I've noticed in my town, I have a different type of SIM card to my friends and have terrible mobile data. My partner & friends get plenty! So that's something to bear in mind here.
I believe he was walking around, trying to find mobile data connection OR a driver on Uber who was willing to pick up the trip (many a night have my uber requests been denied as there aren't enough drivers willing to take the journey up). Once he realised this wasn't working, I think he decided to walk home or to his brother's house, or even back to the party (as this was the vague direction he was headed). So, this is why his final moments show him leaving the swing bridge and walking towards Granby Hill area IMO.
I think the plan was: Leave the party, call his friend, get an Uber home. What I CAN'T fathom is why he decided to go across the bridge and under the circular road when he could have simply bypassed that whole detour and gone straight along the road above the swing bridge.
This is where his mother's statements help a little bit - she says in his final moments on the bridge, he walks straight into a dead end, turns around and goes the opposite direction. You would only do this, in my opinion, for two reasons: 1: you need to pee somewhere private. 2: Youre lost. In some of the CCTV images it looks like he could be quite focused on his phone, IMO he is looking at maps.
So the plan went from leave party, call friend, get uber, to: Leaves party, has no signal, walks aimlessly to find some, gets himself slightly lost, checks maps while simultaneously trying to book an uber, no luck with the taxi, finds his way off the swing bridge, attempts to walk home or back to the party.
I have to say, this case has always reminded me of the Caleb Harris case, in terms what I think happened. It seems likely he went into the water STATISTICALLY. But I can't deny that, at the time he went missing, Jack was not near enough to the water to fall in. With Caleb, due to his history of messaging on Reddit for hookups, everyone assumed he'd left the house and been kidnapped by a late-night friend: this explained how a young man could've simply disappeared off his doorstep without a trace. In actual fact, he was found weeks, if not months later, in an open manhole which connected to a sewage tower. Around 50 feet from his home.
There is a chance, and this is often where I land with Jack's case, that he is deceased nearby, but not in the water. The former harbour master's testimony is telling. I think Jack could be very near the water, in undergrowth, in an elderly woman's poorly maintained garden, in a ditch. This is morbid but it happens, and no more morbid than the theory that he is in the water. I am not convinced he is alive, unfortunately, and I think of him and his family daily. But I do think, and hope, that there is a chance he will one day be found and get a proper burial as he and his family deserve.
In terms of your theory about a driver - When there's a 100,000 reward for information, I certainly wouldn't bite my tongue. Not for somebody I didn't know. Especially when there's a grieving family relying on it. However, I agree with the principle that someone must have seen or known something and has not come forward for whatever reason. All MOO
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www.findjackosullivan.co.uk
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