It's not. Think about it. The Scotsman fallacy is when you claim that no member of a group meets a certain criteria that is not a defining criteria for that gr

It's not. Think about it. The Scotsman fallacy is when you claim that no member of a group meets a certain criteria that is not a defining criteria for that group. "No true Scotsman wears green shoes" is a fallacy. "No true Scotsman is born and spends their entire life in Singapore" is not a fallacy, because someone born in and spending their entire life in Singapore would not meet the defining criteria of being a Scotsman in the first place. "No one sane believes that" implies that the belief that cops should be able to execute people on the spot is incompatible with the definition of sanity. Given that sanity is ill-defined, it's a reasonable (if slightly hyperbolic) statement.