I admit that I have drunkenly walked in the wrong direction for miles, it happens. The two main routes from Bury to Honington involve the A134 or A143, which are both single-carriageway A-roads with villages every few miles. In the dark these would look similar to the A1101 towards Barton Mills...
Hi, first-time poster here. My thoughts during the first couple of weeks of this case were that he walked towards Barton Mills on foot and had an accident. I still consider this a likely explanation.
I would rule out AWOL (why start an AWOL escape with excessive drinking?!), military abduction...