Not too much, actually, unless you were there when he executed a wounded Afghan fighter who presented no danger to him, or, you were present at the various court hearings including yesterday's in which his charge of murder was reduced to manslaughter. The Daily Mail, and numerous worthies, have mounted a veritable clamour of support for Sgt. Blackman in which they seem to blame everyone for his actions except the man himself who pulled the trigger. The entire chain of command was at fault, according to The Mail, from his Company Commander up to the Generals. One has to admit that there is a ring of truth to that given one's natural scepticism of the abilities of the officer class.
Also, they make much of the fact that, in essence, 'war is hell' and that therefor Sgt. Blackman was under severe mental stress. Well, no-one could argue against that but even so, it wasn't one of his team who were suffering equal stress that pulled the trigger, it was him. It is also of interest that the defence called not one, not two but three 'psycho-babblers' to 'prove' that Sgt. Blackman was suffering with, er, "adjustment disorder"! I bet he was given that he had taken part in a fierce gun battle but so to had his comrades who somehow managed to keep their trigger fingers under control.
I'm just exceedingly glad that I did not have to weigh this case and come to a conclusion.