The NHS...
.. employs (both perm and contract) a LOT of people who have access to a LOT (pretty much EVERYONES, all in all, "Private" too, so not just the serfs) personal medical information (history, pharma requirements, ailments, lifestyle) as stored on, ahem, "super high security clinical systems" ( which they only get access to by, er, asking for the login details of a friendly doc, or practice manager...that's if it's not just commonly %systemname% / %blank% or similar).
I can see why the PCTs may want to retain as many of their IT staff as possible, and as Alacrity suggests, treat em well - certainly those who work on clinical systems day in day out, as many do. Or at least make any parting of ways amicable, if at all possible.
One could envision a situation where the disgruntled tech might be inclined to siphon off and sell that information to less scrupulous...oh hang on, I mean, insurance companies, just for example. Or worse (arguably) to criminal organisations (other than insurance companies and governments), who could punt cheap drugs at them, blackmail, extortion etc. Still, if the Gov'ts get their way with all their supergay uber databases, ( Spine, National CRS etc ), I'm quite sure the `big boys` will get all the unfettered access they desire anyway. "Secure".... Meh. : /