The WT is all about half truths. Given that an active witness is only a follower because they believe that the Governing Body is God's agent on earth. Anything that weakens that mindset is dangerous.
If they said MOST, but a person's personal experience taught them otherwise, it has a chance of weakening the hold on a member's mind. With the word SOME, if a person's personal experience taught them otherwise, then they would assume that while it wasn't a scenario they recognized, it must be the case to someone else.
I haven't picked up any literature for years, but it used to be extremely hard to find anything definate in the WT publications. "Facts" are more often than not a question or insinuation. This allows unlimited room to backpeddle and blame the individual for jumping to conclusions if the "facts" turn out to be wrong.
A thing that bothered me was the frequency that they would ask a question in the negative like this: "Would you not agree...?" So much emphasis was placed on the Faithful and Discreet slave being true that the essence of the question mentally resolved to "Is your opinion contrary to the that of the Governing Body" Given that having a contrary opinion is deemed as wicked, unfaithful and Satanic, the mind just accepts the question as fact rather than challenge itself to form a contrary opinion.