The Farm Hand<br>Mildred took over the farm when her husband died. She was very old and inexperienced. She hired a farmhand named Mark. He turned the farm around and saved her business. Mildred was so grateful!
Mildred and Mark own the farm together
From the context Mark is just a farmhand, whilst Mildred is the one who owns the farm. Mark has no ownership of the business. The system could likely not differentiate between owning the farm and working on it 
( z1 own :ARG0 ( z2 and :op ( z3 person :name ( z4 name :op "Mildred" ) ) :op ( z5 person :name ( z6 name :op "Mark" ) ) ) :ARG1 ( z7 farm ) :mod ( z8 together ) )