It is the airline's duty to inform passengers sufficiently such that they do not panic
It is in the airline's interest to inform passengers of technical issues in such a way that will attempt to allay any concerns that they may have.
It would appear that the situation was not controlled by cabin or flight crew adequately to ensure that SLF concerns were defused before the situation reached a point where the Captain considered that takeoff was inadvisable given the disturbance in the cabin.
