premise: Northwest Strikes: If Northwest flight attendants go on strike on the 15th, what does that mean for travelers? I have a trip booked on the 24th. Will NW rebook us with other airlines?
hypothesis: If Northwest flight attendants go on strike on the 15th travelers will have to book other flights.
reason: Based on the text, we don't know what will happen if Northwest flight attendants go on strike on the 15th, so the statement is neither definitely correct, nor definitely incorrect. I think the system got confused because the first part of the statement is correct and the ending is a little vague, so the system decided it is more likely that the whole statement is correct.