It's not really about where the phone is now, it's about how it ended up there.
If it was IN the bin I would say there was foul play - Corrie didn't have it in his hand when he rounded that corner so it's unlikely it was thrown away by him by accident. Had he left it in the doorway, or had he been mugged? A random, innocent person wouldn't just throw a random phone in a bin. I don't know where the mugging rumours came from, but it might make perfect sense that someone grabbed it from him while he was in the doorway (maybe at 3:08 when he had it in his hand) and, realising it wasn't of much value, they threw it in the nearest bin as they ran off. To me though, Corrie didn't look in fight or fright mode on the 2nd CCTV, he had his hands in is pockets which doesn't suggest someone who was expecting trouble, I think if you'd just been mugged you'd be looking less casual about it. I think he was just desperate for a wee.
If it was ON the bin there's a chance he put it down and forgot about it.
If it was found by the binman (or anyone else) and taken then tossed away, they needs to own up.
The reason for it being in that bin lorry is pertinent to what might have happened to Corrie, regardless of where they both are now. But then it might not have ever been anywhere near the bin lorry, the binman or anything to do with the bins at all. It might just be coincidence that it followed roughly the same route as the bin lorry and at roughly the same time. It might have been left in the doorway and someone heading home to BMills picked it up and later chucked it. It apparently didn't move from 4:30ish and lost power at 8.
Anyway, that's this mornings thoughts and ramblings by me. I still think he'll be found somewhere near that roundabout.