Private insurers - the real death panels
If we are going to use the term "death panels"...you're correct that our US private insurance companies would fit that description much more closely than anything in the UK courts or UK healthcare system...although, I'll say, anytime someone uses the term "death panels", it's almost always emotionally charged hyperbole (which, I'm sure you were doing it intentionally in this case to illustrate the absurdity of the other poster's claim).
However, in this case, I'm pretty sure that a few people are merely employing this hyperbole to further their political stances, both against the UK healthcare model, and in favor of their conspiracy theories about mainstream medicine.
Let's be honest, if this were a story about US parents wanting to take their child out of the hospital for medicinal marijuana, and a conservative judge in their home state blocked it, those same folks would be taking the polar opposite stance and siding with the judge... But, because this is a left-leaning court in a country with universal healthcare, they're pretending that this "experimental procedure", which is nothing more than a modern $750k version of "snake oil", is somehow a credible treatment, and "that evil UK court is giving this baby a death sentence when a cure is available".
If you notice, in all of my previous posts attempting to delve into the details of what this procedure is, and why it's eerily similar to how the Burzynski Clinic operates (showing all of the red flags for being exploitative alt-medicine), they ignore it and have no interest is discussing that, and instead circle back around to one-liners about how "the courts are playing God" and "this is a matter of life and death", etc....