To work through a possible abduction scenario, I thought about this the other night.
What I envisage is grabbing someone, bundling them into the back of a van. As soon as the van doors are almost closed, the driver starts driving. Inside the back of the van, the abductee is slapped around to subdue him, then his hands and feet are tied, then check pockets for phone and wallet (for ID), then dump the phone. So the phone gets dumped maybe ten minutes traveling time post-ambush. I would just hand the phone to the driver, or someone in the passenger seat and have them throw the phone out the window into bushes at the side of the road, and then I'd keep driving.
Does this sound reasonable? How does it fit with what we do know?
I ALWAYS try to offer up a positive to any suggestion. That's how constructive critiques work in my mind. Your theory is plausible apart from:
1. A quick 'grab' would probably mean a quick escape. Having tracked the updates on the phone and establishing that it travelled towards BM mast area at a slower speed (I worked out approximately 11-20mph within the signal areas) than a normal vehicle. That kicks your grab theory into the long grass.
2. Why throw away evidence? If you're driving a van it's reasonable to assume that the driver has special awareness to be able to negotiate the narrow streets and so would presumably understand that to throw a phone out of the window would be foolish.
3. The signal was tracked towards the BM mast area. That's pretty late on in the ambush scenario to lob it out of the window then. That suggests a really in proffessional job.
What does work for me is a serious mugging in Shortbrackland followed by this possible sequence;
a. The muggers making off with the wallet and phone (explains the arguing teenagers) then,
b. The muggers (teenagers?)realising that the phone is of no financial importance from a resale point of view because it's old and it's also locked then
c. Throwing the phone into a passing bin lorry (explains the signal track) then,
d. On realising that there is military ID in the wallet and the potential consequence of their actions, taking the cash and secreting the wallet somewhere (local bin, under soli, gutter, roof, toilet cistern etc...),
e. Bundling Corrie into (there's three teenagers remember) a yet unknown location).