To me, as an American, this whole case is repugnant in the extreme. The handgun at the heart of this matter is in no significant way different from the handgun which I carry, concealed on my person, on a daily basis. It is in no significant way different from the thousands of handguns sold legally over the counter every day in this Great Republic.
That Britain and the Commonwealth Countries see fit to treat these self-defense weapons as contraband, to be gathered up and destroyed by the government, the mere possession of which is ground for years of imprisonment is appalling. Your weapons laws (like ours ... indeed like any) serve only to harass the honest peaceable citizen.
The thing is - being SAS, he should have been able to get a PPW (Personal Protection Weapon) licence. They are very difficult to get in the UK (I actually have one for reasons I’m not allowed to discuss), but SAS have never found it difficult to get them, because of the risk they face from certain Irish terrorist groups. The fact he doesn’t seem to have had a PPW makes me wonder what else was going on here, that isn’t being discussed.