Chaucer: robbed in Hatcham

Some people like to look back to a golden age of crime-free New Cross, but I'm not sure how far back you would have to go to find it. Presumably further than the 14th century, when Geoffrey Chaucer was robbed in Hatcham, as the area was known in those times. As A.W. Ward described it in his biography:

'Though by the latter part of the year 1391 Chaucer had lost his Clerkship of the Works, certain payments (possibly of arrears) seem afterwards to have been made to him in connexion with the office. A very disagreeable incident of his tenure of it had been a double robbery from his person of official money, to the very serious extent of twenty pounds. The perpetrators of the crime were a notorious gang of highwaymen, by whom Chaucer was, in September, 1390, apparently on the same day, beset both at Westminster, and near to "the foul Oak" at Hatcham in Surrey'.

I wonder where the 'foul oak' was? Presumably somewhere on Watling Street (now the A2/Old Kent/New Cross Road), the old road from London to Kent upon which the pilgrims of Chaucer's The Canterbury Tales tell their stories on their journey from Southwark to Canterbury.