The accountability I was referring to in my earlier comment wasn't about legal accountability, I was referring to accountability to the God they profess to be representing.
The Societies literature indicates that a JW could be held accountable/ blood guilty by Jehovah for the lives of the householders if he or she doesn't spread the "good news" to them at every possible opportunity.
If one can be held accountable to Jehovah for not spreading the good news, then it seems reasonable to conclude that one could be held accountable for spreading incorrect information that could bring harm to a potential follower or cause them to turn away from the message because they can see that the humans supposedly delivering Gods message are misrepresenting him or don't know what they're talking about.
I'm sure it could be proven in a court of law that based on what their leaders have insisted upon, JW's are intimidated into refusing blood for fear of displeasing God in a big picture way and fear of losing their friends and family if they don't comply.
We've seen in the past how when the rubber hits the road, the Leaders claim that each JW is free to choose their own actions and that no disciplinary action would be taken against them. Yet we all know the reality of it. If a JW takes a Blood Transfusion, there will be consequences. If an elder, pioneer, ministerial servant were to take a blood transfusion, they would no longer be able to continue serving in those capacities. At the very least a JW who accepts a blood transfusion would be viewed as a weakling, as having failed Jehovah and would be a big disappointment to everyone he knows and loves.