It was fit to go to the jury, as questions of fact, and they acquitted. Nothing new in that. 40 years ago I saw someone acquitted, by a jury, of s18 when he'd shot a mere intruder in his scrapyard. A few weeks ago a man was not, I think, even prosecuted when he fatally stabbed an intruder. A few years ago an employee in a gun shop shot dead one of two men who were threatening the proprietor. He wasn't charged .
The law hasn't changed,it's just there's an obsession in the popular press with such cases lately.