The idea you cannot leave the horseshoe without being detected has been BS from the start IMO. It's only now that I see it's probably being touted like that to make someone feel guilty that they are "caught red handed on CCTV" in an effort to get them to come forward. The reality is they probably got away scott free. The other issue is that they wouldn't even have to TRY to evade CCTV for them to fall into the 80% likelihood of being able to anyway.
Greenwoods CCTV cam looks at Corrie's alley for 30 seconds and then elsewhere for 1min 30. If you ain't seen in that 30 seconds, you can go wherever you like from the Horseshoe up Short Brackland and never be seen again. ONLY if you go up towards Greenwoods (like 4 min lurker) or past Cornhill (like running man) will you actually be definitively seen on CCTV again.
Why is Corrie not seen on Greenwoods CCTV after 3.24am? Cos for every 2 minutes of footage it's only looking at the horseshoe for 30 seconds. Someone may do the math and work out how much time that actually equals between 3.30 and 8am. If he and other party (if involved) never went past Cornhill, there's a seriously high chance they'd never be detected again. Personally I feel foot and vehicle could both still be in play, because you can "evade" the horseshoe CCTV on either, and evade the CCTV further out from the horseshoe also on either foot or car.