The incident, described as savage and appalling, happened in 2019, in a car, when Guildford was extremely intoxicated.
“The brutality and considerable force behind the blow is illustrated by the nature of the injuries caused to the victim,” Justice Paul Davison QC wrote in a decision released after an appeal in the High Court at Hamilton.
“It was clearly serious offending, and the fact that it took place in the context of the appellant being severely intoxicated by alcohol is no excuse whatsoever.”