Is there a written requirement to spread out the damage? Obviously not.
Yes, some of us are angry and upset by the outcome of our adventure.
Arguing amongst ourselves and insulting each other isn't going to fix this adventure.
This adventure still needs a "Bone Keep" style disclaimer about how dangerous and deadly it is. Players 9th level and below will die.
The paragraph of box text just before the first encounter is misleading and should be rewritten.
Start with those minor issues first.