How can you know that they wouldn't have had private medical insurance if that were the system in the UK? The Gards did not create the NHS.
1. That's not really relevant here. I don't recall the Gards clamoring for private medical insurance six months ago -- do you? Like I said -- they were perfectly fine with "the system" when it worked for them. I don't blame them for this. I'm just pointing out the paradox at work here.
2. If they had private medical insurance they would run into the same problems with someone making a decision where an experimental treatment would be rejected. The only difference is that the decision would be made by an insurance company employee rather than a government bureaucrat. And at the end of the day their final recourse would be a court case against the insurance company ... which puts us right back here with a government-paid judge making a life-or-death decision.
I'm not trying to be funny here, but it's worth noting that you never see cases like this involving Amish people. That's the trade-off they've made to preserve their liberties, and there are both positive and negative sides to it.