The owner of the Pizza Mamma Mia takeaway states that Corrie buys food there about every 2 to 3 weeks so we can assume he was a regular customer there. The owner would have known if Corrie regularly bought that amount of food, or if that particular day he bought an excess. Additionally, we do not know if it was unusual for him to be alone buying his food or if that was normal. Obviously we do not know although the police surely do. I have to say though, that personally and from experience I don't find 2 burgers, chips and a kebab excessive for a 23 year-old man!
Corrie has been at RAF Honington for 3 years. If during that time he went to BSE every 2 to 3 weeks due to the statement from the owner of Pizza Mamma Mia, he must know BSE very well. Can we therefore assume that his walk towards Hughes doorway with his food was something that he had done previously, perhaps even on a regular basis? By association, he would also have known the horseshoe area. My point here is that he most likely wasn't walking into a blind alley, it would have been somewhere he had been before, whether to relieve himself after the drinking, or for other unknown reasons.
There is so much information that we are not privy to, but on what we can surmise and taking a path closest to normality, I would suggest:
Corrie gets up from Hughes doorway (I would really like to know what he was doing between 3:08 when he last used his phone and 3:24 when he entered the horseshoe area).
He enters the Horseshoe with the sole intention to relieve himself. He then approaches a parked vehicle that
perhaps he recognises with occupant/occupants inside. He enters the vehicle and they sit talking or engaged in some other activity.
When the bin lorry arrives the occupants in the parked vehicle are perhaps disturbed by the noise, or feel that morning is not too far away and there will be an increasing number of people entering the horseshoe, so they decide to drive to a more secluded area out of the town. At this point I am in agreement with
MidsummersDay, in that they are driving behind the bin lorry towards Barton MIlls. However, perhaps they were a minute or so behind it, as surely when the bin lorry driver was interviewed by the police one of their first questions would have been "was there anyone driving directly in front or behind you?"
The above would explain the phone pings, and take out the phone ever entering the bin scenario.
Other than perhaps the phone battery giving out, what happens next we just don't know.
JMO
Links to the above information we know to have occurred are found on
http://www.findcorrie.co.uk/