Question

Hello Rabbi, 
 
Regarding the commandment, “And you shall do according to what they instruct you” — I understood that some limit this only to the Sanhedrin, but the question I’m going to ask concerns those who broaden it, maintaining that one must also listen to the leading sage of the generation, or even to a local rabbi. 
 
On March 14 it was decided not to allow gatherings of more than 10 people, and also to keep a distance of 2 meters between people.  
When Rabbi Kanievsky, may he live a long good life, was asked on that same date whether the study halls and yeshivot should be closed (link attached below, around 50 seconds in), he answered, “Heaven forbid.” 
 
However, on March 29, there was a drastic change in his position. One could even say that his position did a 180-degree turn, to the point that anyone who does not follow the Health Ministry’s instructions has the status of a pursuer. 
 
Although by March 14 it was already fairly clear (at least here in Israel) that the coronavirus was killing far beyond “just an ordinary flu,” I am convinced that Rabbi Kanievsky was not aware of the full severity of the epidemic when he was asked by his grandson (in the link below).
When the Rabbi was presented with the full information, then apparently on March 29 he issued emphatic statements in the opposite direction. 
 
My question for the Rabbi is: according to the view of those who broaden the scope, is there room not to follow the words of the leading sage of the generation if there is reason to suspect that the data were not fully presented to him? 
In other words, is there any discussion in Jewish law that limits in some way the commandment of “according to what they instruct you” in situations like the above? 
 
https://www.youtube.com/watch?v=SLk5B4V6AHs
 
Best regards, Ehud