Pointlessly amused by this, as the obvious acronym would be DESERT.
Also, placemarking as am pointlessly fascinated by this story. I used to live next to Wandsworth prison (Alma Terrace, for locals) and inmates were always escaping. Now and again they'd run over our rooves. We heard hair-raising and sometimes disturbing stories in the pub, from the staff coming off shift.
That was a very long time ago but I keep loosely up to date, and things have very definitely not got better at HMP. That's from a low starting point. I don't know how they - staff or inmates - cope as well as they do. The place has a reputation for relatively 'good' atmosphere, which is something of an achievement by the people running it.
Anyway, I'm unsurprised by the success of this escape and somewhat charmed by the 1960s-movie-style method! No idea what Khalife has actually done ... but, yeah, Richmond Park would make a decent hiding place if he hasn't been supported by an organised scheme. Only very short term, though: he'll need some nearby friends to take him in & smuggle him away.
Rory Stewart was mentioned upthread. What a loss to British politics.