If Karen was going out for what ever reason that early in the morning don't you think someone would have been expecting her?
If she was returning to the Halloween party I would think she would have called someone to see if the party was still in full swing. That person would have come forward and said something like "ya, she called me and she said she would be here in a half hour"
If she was going to meet up with someone I would think she would have had plans for that too. That person would have come forward by now and said "ya, she called me and planned on stopping over but never arrived" or "ya, we had plans for her to take care of her daughter and then stop by my house later but she never showed up"
We know she arrived at the house around 1:30 AM and went to bed with her daughter. For her to get up sometime between 1:30 AM and 6:00 AM when the car was found and not communicate or have plans to meet someone, if she was planning on leaving again would seem strange to me.
As far as we know no one has come forward and said anything to the fact that Karen had plans to leave the house for any reason that early in the morning.
I think her phone records will be a big part of solving this case. Did she call or text anyone that early in the morning? Who just leaves that early in the morning without a plan of going somewhere or meeting someone? Has LE released the time at which the phone shut off? We know the phone pinged or was used near a river when it shut off. The phone shut off from likely being thrown into the river. What time was that? Would the husband have had time to drive from the area at which the phone shut off to where the car was found, walk to the house before the children woke up? If I remember correctly the husband is the one that was said to have found the car at 6:00 AM and the daughter awoke at 6:30 AM. Did the husband wake up the daughter at this time? Did he call anyone at that time he found the car to see if Karen might be with them or was anyone with him to verify this time? Did he seem concerned that the car was parked down the road with a flat tire but Karen was no where to be found? Does the vehicle have GPS that can be examined to possibly tell where the car was driven and at what time?
The only other possibility for leaving that early in the morning unannounced could be she might have gone to get something for her sick daughter such as medicine, but I would think what ever she had purchased would have been found inside the car along with a receipt. Are there any stores open that late at night and do they have surveillance video? I would think a store clerk would have come forward by now and said Karen was at the store in the early morning hours by now if that was the case.
Looking at the Google map in the following link showing where Karen's house is in relationship to where the car was found and the image below pointing out the spot where the car was found it is possible that when Karen left the house and drove on Harness Rd. towards Millsfield Hwy. her tire could have gone flat as she approached the intersection of Millsfield Hwy and Harness Rd. She could have then turned right onto Millsfield Hwy and then did a quick U-turn to park where the car was found in the direction in which she did. So I think it is possible that she could have been leaving the house for the car to be parked where it was found with a flat tire.
Examining the tire it should be easy to tell what caused the flat, whether it was cut, the air was let out or if a nail or some other object was in the tire that would have caused the tire to go flat. If the car has sensors to tell if a tire is low it may be possible to scan the vehicles computer to tell what time the sensor was triggered. Most cars will record a log of all codes or faults a vehicle will experience. This could give us a clue as to what time the tire went flat and the car was parked. If the tire went flat before the phone went dead than that points towards a stranger abduction. If the phone went dead before the tire went flat that would point to the husband being the likely suspect in my book.
http://maps.google.ca/maps/ms?msid=...ll=36.135379,-89.386193&spn=0.006776,0.009645
All JMO