Bews, Saxby and Bonnet all timed their dispatch to WHF at 3:35am. This means the clocks and watches of CA07 and Bonnet are all in sync.
Bews and Saxby both agree they arrived at WHF at 3:45am
Bonnet heard of their arrival at WHF at 3:48am. This can only be the result of a delayed message from CA07 confirming their arrival at the scene.
Bews and Saxby both agree that Jeremy arrived two minutes after they did. Thus they have Jeremy arriving at 3:47am
And So.
Jeremy calls West at 3:36am and has two conversations with West while also being on hold for six minutes in-between. This means Jeremy got off the phone no sooner than 3:44am.
He then must drive at around 84 mph in order to reach his destination 4.2 miles away at 3:47am. This also allows no time for Jeremy to call Julie, get the car keys, and put clothes on.