Because regardless of the strength of their belief in the WTS teachings, they had authority over this women vested in them and were duty bound by the dictates of their own conscience to search their hearts before they gave Sarah Berry advice.
But didn't the mother also have authority over her children and isn't she duty bound by the dictates of her own conscience to search her heart before acting on advice?
I understand your points about climbing the ranks of authority and increasing culpability, but where does the buck stop? Eventually, you could cast blame on the Bible and God for their "influence" on the matter.
Is it unfair that they are being sued for holding to similar beliefs as the mother? Perhaps it is, but that is beside the point.
That may beside your point, but it is exactly my point.
The designers of the drug Thalidomide felt that they were doing a service for mankind in manufacturing this drug. It came to blight the lives of many of the people it was designed to help. Perhaps they should not have had to pay for their error because after all, the outcome was unexpected? This is of course nonesense. They had authority over the user and even though their motives were unimpeachable and their belief in the product absolute, they had to pay for the misuse of this authority.
This example could also aptly apply to the mother and her authority over her daughters.
Again, I'm sure we will have to agree to disagree.
In conclusion, I'd like to make known that I do not mean to harp on the mother, nor do I think she should be punished. I think she was wrong in her decision on reporting and made a tragic error, I think the elders were wrong in their decisions and made a tragic error, I think the father is evil and deserves what he got (assuming justice prevailed and he wasn't an exception to the system, I don't know much about the case.)