The probable picture...
From having worked in NHS tech, the probable picture is more like:
A PC reboots in an operating theatre. PCs in operating theatres tend not to have much on there apart from access to the databases of what's next, and what's going on. It's an inconvenience, but not a showstopper. The really imporant stuff is non-windows, and that's the stuff that keeps you alive.
Now, one of the consultants is likely to have been most peeved by this, and demanded an instant assurance from the trust board that this doesn't happen again. The trust board let IT know that it needs to be fixed NOW. Don't think about it, just stop it happening.
Trust IT are usually completely overworked (try 5000 users, with one sysadmin, one DBA, one Network Admin and 6 people to fix PCs, all that to support all the external vendor supported systems, plus stuff the local devs do, the security, the patching, the planning, the documentation, the management of systems etc.).
The likely event is that the decision was made to hold back updates until all the policy could be implemented to split the main load of computers apart from the Theatre ones, and the admin(s), if they had an admin team (some hospitals share people amongst several sites, and rely on vendors for support of all the machines they have; a LOT of NHS vendors keep trying to say "You don't need local admins, buy from us, and we'll look after the application on the machine for you". Without saying they won't keep machines updated or anything else like that, and some trusts, not knowing better, go with it, especially the small hospitals), being told, "Just turn it off until it can be fixed. Directive from the Directorate".
The reason Windows in in the NHS is because all the developers code for it (the amount of medical software that is Windows/SQL Server/IIS only is the huge majority). Which means it needs to be implemented. And there are also huge Microsoft deals making it cheap to install Windows.
So, because of budgetary constraints (no NHS hospital has enough funds to run well at the moment; the 'Targets Culture' has meant huge amounts of money having to be spent on ticking the boxes, or being fined by the Government when you don't manage to, Which creates a vicious circle of "Can't afford the resource to meet the arbitrary target set by the Government, so they fine you, taking what little you had away from you, making you miss more targets") , you end up with too few staff to do the real work, but because everything usually keeps pushing out the number, the Directorate consider that all is ok. And if everything just works, they cut back more on IT, making it a prime target for cuts at every stage.
NHS IT is a bind. You're overworked, understaffed, under resourced at every stage, with a group of competing Medical departments all pushing for arbitrary systems to be installed (sometimes with a day's notice if you're lucky), all wanting things to be done. Yesterday.
Yeah, this kind of thing is likely to happen in a large amount of the hospitals around. There is an easy solution (and it's not "fire the teams there"). It's called "hire the right size of team to do the job, with extra qualifications and experience to complement the existing skills".
However, that costs money. And it comes back to the NHS not having any, so requests to expand the team will be met with a resounding "No".
Oh, and for all the people out there saying NHS should use Linux.. It does. It has a standing deal with Novell, and using several other flavours in various trusts.
As well as using Solaris, AIX, Netware and a whole host of other operating systems too.
It's nice to have a big team of people looking after a homogenous network (been there, done that; it's quite comfy)..
Seriously, spend a bit of time in NHS IT, with a tiny team (if there is a team) supporting several different OSs, databases and applications with little to no time for research, testing or even basic infrastructure maintenance (that costs money for resource that isn't there). Again, been there, done that, and it's NOT very comfy at all.
The choices for IT are basically: Keep the systems secure and well maintained, but the doctors and medical staff up in arms about the maintenance outages. Or keep the place running and operational, but just barely.
Oh, and if you choose the secure and maintained, Directorate overrule you because of complaints by Medical that nothing gets done.