Just an update with the information you kind people have provided, in this thread and subsequently -
There's an article in the Belfast Telegraph on 27th May 1957 which reveals that earlier that day Pilot Officer C.R.Baker (19) made an emergency landing in a field at Lyng, near Dereham, Norfolk, whilst on a training flight from Cambridgeshire in a Vampire jet fighter.
Using that date, I discovered it related to a de Havilland DH.100 Vampire FB Mk 5 jet (number WA259) from Oakington which crashed 27.5.1957 when it lost power due to an engine fire mid flight and was wrecked in a forced landing near Primrose Green, Breckland, 4 miles east of RAF Swanton Morley, Norfolk, with “No reported injuries to pilot”.
Whether he broke his legs as reported in the anecdote I cannot say, but it wasn't recorded on the paperwork.
You've all been extremely helpful. It all stems from Brakedwell's incredible memory and I am very appreciative.