A waiter who refuses to accept the credit card of a part owner of the establishment is already brain-dead and thus shooting him is an act of kindness. The 7 years gaol term is probably for breaches of civil statutes such as noise abatement, releasing toxic substances (lead) in a place where food is prepared, creating public mischief ( by further delaying the service of food and drink), employing a person of unsound mind................ and so on.
Seven years is a harsh sentence for what was effectually a community service................