Op Yabu so very much. This is disgusting and deplorable. The government and people like you need to think more highly of our forces and veterans. He would not have shot him for no reason, that's bollocks.
Why? Some of our forces and veterans are total dickheads. Don't be fooled into thinking they're all angels.
Equally though, OP - don't believe everything you read in the media. They can only ever tell you half the story.
For example, if the true facts about Marine A/Alexander Blackman had been publicised, I'd wager far fewer people would be campaigning for his release.
In short.... Don't believe everything you read and remember.... You weren't there.
I say all this as the wife of someone who served over 20 years in the Royal Military Police and saw the best... and worst.... of The Army during his time.