As someone mentioned you have to switch back to the perimeter road after Hatton Cross to get to the River Crane
That was me and I owe you an apology ..it appears you can stay on the A30 footpath eastbound until about 400m east of Hatton X, then go to the LHS of the walled Picaddilly tube line cutting and you are almost at the Earhart Way barrier.
Glad you enjoyed the walk, but yes, it's has been a bit wet recently...