Wrong implication.
Shep's only a human being.
He has emotions. He has stress. He is not a robot and perfect in any way.
Sheps not giving water to folks who need it, because he needs it.
You are lacking in compassion for insisting that he
a) Make himself dehydrated
b) Open himself up to being killed by a mob.
You see the same thing with soldiers. I have seen soldiers interviewed who feel bad after some event because they couldn't hand over their own supplies.