Speculation alert:
Call me strange.. but I think AB may have thought Z was home in bed sleeping/resting to get recovered from a stomach virus. (and no, I wouldn't award him Father of the Year with lapses in judgment like this, among other parental failures)
Note: Hickory Oktoberfest started on Friday Oct 8 and went until 11 pm that night.
I think during Oktoberfest (Friday evening/night) IS the timeframe the dismemberment/dumping of Z's remains occurred.. and believe it or not, I think neither EB nor AB actually had a hand in it. (and, IMO, AB had no knowledge of it). Ironic, but I think it would fit EB's style to "set up" others to do this dirty work. And with the sorts of allegations we heard this week, there could have been others willing to take this on to ensure their own misdeeds were concealed. (I am not making any accusations here against the two who were named in those allegations.) I think EB was involved in other cover-up tasks (i.e. dumping the mattress earlier that day - or possibly the day before).
I think EB likely convinced AB to go to Oktoberfest to get him out of the house so *other* accomplices could have access to the house and vehicles. I think there were probably 2 or 3 accomplices (possibly even 4).
I think the accomplices did the dismembering, then 2 of them split up in the (company) Tahoe and the 1990 Camry to go distribute Z's remains. I think it's possible a 3rd (maybe 4th) stayed to clean up the crime scene at the house.
I think the 2005 Impala on the search warrant (the car with NO decomp hits on it) is likely what the Bakers would have driven to Oktoberfest.
I think the accomplices were very hurried to get everything done while the Bakers were out.. hence the "goo glove" dropped and left behind with no time for double-checking things.
I think EB was "briefed" by the accomplices as to the dumping sites. And IF there actually are discrepancies between what EB said (in the warrants) would be found and what was actually found at particular locations - I think she had either misunderstood or misremembered what she had been told (by the accomplices) was where.
Big-time speculation, I know. But I really think the story could be something similar to this when it all comes out.
And because I wholeheartedly believe there were accomplices in on this - I again, sincerely urge these accomplices to do the right thing - for a change. Go speak with police.