Thanks for signposting to this @Officer Dibble
. I've been looking at CCTV images while I eat lunch.
The area isn't well covered unfortunately. There is one traffic camera over the road from the tube station, at the junction with Alfred Street. It points west down Bow Road, so doesn't cover the tube station directly, which is a shame. The northside pavement is also obscured by tree foliage, so if he turned right (east) out of the station or turned left but crossed the road before Alfred Street, he would not be caught by it. The camera captures images every six minutes, so there's also going to be a lot of faster moving activity that it misses completely.
There's very little foot traffic. I looked at images from 12 noon to 3pm and saw fewer than 20 people on that stretch of pavement. I've pulled one that might be worth a closer look. It's at 1pm exactly and seems to show a tall man walking along the cycle lane in reddish shoes, which is unusual, and fits the description. The resolution on these traffic cams is awful and black or white shoes tend to disappear into the pavement, but these have a bit of warmth to the pixels (it's more obvious if you've looked at a lot of CCTV images). However, the person is walking east towards the tube station, so if it were to be him, then he must have left the tube station a bit earlier than stated and had time to walk west a bit and either find a toilet or give up before coming back. It also seems like the man's top is dark, not white, so I'd be interested to know how complete a description that was, or whether he also had a dark jacket or jumper, say. It's very hard to tell though.
On the balance of probabilities, it's unlikely to be him, but I echo whoever said that his family and friends need to be canvassing along that stretch of road for CCTV from private sources before it all gets deleted.
The other thing that occurred to me is that Bow Road is a well served bus route. He probably had an Oyster card, so if he left the tube station, realised it wasn't a great place to find a toilet and a bus went past right at that moment, he might have jumped on it thinking to jump off again a couple of hundred yards down the road. If he knew the area, he might have reasoned that Mile End would be a better place to go, intending to jump on another bus right back again, but failing to for some reason. So I would also be asking TfL for bus CCTV, again before it's too late.
Similarly, I wondered if he might have been likely to use one of the Boris bikes from the stand at Bow Road. Perhaps someone should enquire if one was taken and not returned that day.
Just some random thoughts.
I'll attach the traffic cam image. It'll probably need saving and blowing up to see anything.