I really don't think their minds wrapped around the idea that the cadaver smell, pants, gas cans and their missing granddaughter were in any way related. It seems obvious to us -- we're always prepared for a murder on here, but that's probably just not where anyone's family's mind would go initially. I mean, it's not as if they had ever considered that Casey would kill Caylee, or that Caylee could be dead, just like that.
The only thing that has really bothered me about their actions is leaving the incorrect missing date and an incorrect phone number on the web site for quite a while after they knew of the error. I just don't get it.