Salix Homes is a housing association in the City of Salford, Greater Manchester and based in the Langworthy area of the city. It manages 10,500 homes in the Central Salford part of the district which includes Claremont, Weaste, Seedley, Kersal, Charlestown, Broughton, Ordsall, Langworthy, Islington and Pendleton.
Salix Homes has an office in Langworthy
The context states that Salix Homes is based in Langworthy, so it must have an office there. The system could likely not understand that if a business is based somewhere it must have an office there. 
( z1 have :ARG0 ( z2 company :name ( z3 name :op "Salix" :op "Homes" ) ) :ARG1 ( z4 office :location ( z5 city :name ( z6 name :op "Langworthy" ) ) ) )