The fact that he has likely gone there to pee, makes the whole thing "that bit more" baffling.
He had consciously scanned his surroundings to make sure there was no one there, is something that does get overlooked. The loading bay area (and his immediate surroundings) must have appeared "clear" to him. It would appear that there was no one in his immediate line of sight.
The curious thing about that is, it is possible that the bin lorry collected his phone, which may have been in the rubbish bin at the time. If so, that happened 35 minutes after Corrie had entered that area. If we assume that Corrie wasn't in that area at that time, and he had not walked back to his car (no cctv) or walked to the taxi rank (no cctv), then the only route that he could have taken AND not be seen, would be "down Short Brackland".
A debate is "whether or not Corrie dropped his phone in that area". To be honest, I think it is "more likely" that he did not lose his phone, on that night, or in that area.....but that it was disposed of in the bin that was later collected.
Now, that assumes a lot. How do you walk into an area where someone may be, but you don't see them ?
My first thought was, they were hiding. That would indicate it was likely a "random attack" and that Corrie was not a target. How would anyone "know" he (or anyone else for that matter) would walk up to the bin area and have a pee.
My second thought was, you can't see them because they're in a vehicle. If a car is parked up, with no engine running and no lights on, it can be hard to see if anyone is in it or not.
Being in a car would explain how Corrie left Bury unseen and completely disappeared from sight. But a car would have to pass cctv twice...and on both times be unseen. Even though that area is not watched for 2min 48secs in every three and a half minute period, it's still quite a fluke not to be captured on camera, even just once.
If that is even likely, the big question again is, would a "random attacker" go about his attacks, from the comfort of his own car ? It would have to be "random" as again, no one knew anyone would arrive their for a pee. It seems extremely doubtful indeed.
I think knowing more about that area would be useful. Does it have any other uses at night ? Do cars arrive there during the night for some reason ? Do cars park there during the evening ? Has it had any regular visitor ?
Just some random thoughts