NASA's Saturn exploration spacecraft, Cassini , has discovered an atmosphere about the moon Enceladus . This is the first such discovery by Cassini, other than Titan , of the presence of an atmosphere around a Saturn moon.
Enceladus was discovered by NASA.
My statement is neither correct nor incorrect as it's not stated anywhere who discovered Enceladus. Only that NASA's exploration craft Cassini discovered an atmosphere on Enceladus. The system is fooled because, I only used words out of the original statement and I didn't add any words, I only removed/didn't use all of them. The system doesn't understand how the meaning changes when you remove certain words. 
( z1 discover :ARG0 ( z2 research-institute :name ( z3 name :op "NASA" ) ) :ARG1 ( z4 planet :name ( z5 name :op "Enceladus" ) ) )