Bournemouth, Dorset - UK ~ An English man who suffered from Asperger syndrome (a high functioning form of autism) was killed by a single punch to the face during an argument, shocking surveillance video shows.Closed circuit TV captured the moment that Andrew Young, 40, was sucker punched last November by Lewis Gill on a Bournemouth St. following an argument over riding his bicycle on the sidewalk.Young - who his family said had the social skills of a 14-year-old - instantly collapsed to the ground and his lifeless body lay on the pavement as Gill and his two cohorts walked away, the video released for his sentencing shows.Young died the following day at a hospital from his head injury."The sentence is an absolute joke," Young's mother, Pamela, told the outlet. "I'm a committed Christian but I think that if someone takes a life they should be prepared to forfeit their own."The argument was sparked when Young told Victor Ibitoye that riding his bike on the street was dangerous outside a Tesco supermarket on Nov. 6.Ibitoye walked away from the argument with an unidentified female, but Gill, trailing behind, wound up and slugged the man.Young, who was said to speak several languages but was hindered in social situations by his medical condition, was "very particular" about cycling safety, his mother testified.The strapping brute claimed that Young made a racist remark at him, prompting the punch.But Judge Keith Cutler noted that his powerful physique made the heinous attack far more malicious, according to reports."You are a powerfully built young man," the judge noted, according to the Mirror." "You must have known that it was going to cause a significant injury and, very sadly, it did.