The Hammett Prize is awarded annually by the International Association of Crime Writers, North American Branch (IACW/NA) to a Canadian or US citizen or permanent resident for a book in English in the field of crime writing. It is named after crime-writer Dashiell Hammett and was established in 1991.
The Hammett Prize is only available to North Americans
USA and Canada are North American. I think the system got it wrong because the statement requires an inference
( z1 available :ARG1 ( z2 person :mod ( z3 continent :name ( z4 name :op "North" :op "America" ) ) ) :ARG2 ( z5 award :name ( z6 name :op "Hammett" :op "Prize" ) ) :mod ( z7 only ) )