It seems to me that the belief that the child was washed and given clean clothes is only good for the prosecution, but at the same time it is completely illogical. That is, if Jason drove to the hotel, then home again to commit murder, he would not have any extra time to spend doing laundry.
Jason's time line is from 12:01AM to 6:35AM (camera unplugged). The one way trip is 170M and driving time is 2h45m. Without stopping, total travel time is 5h30m. Investigators said that the murder took about 10 minutes. The stop for gas took about 10 minutes. Now he has used up 5h50m. He needed time to change or get a weapon prior to the murder - another 10 minutes ... now we're at 6 hours. That leaves 35 minutes for Jason to calm down after the violent 10 minute long murder, shower, change, get what he needed from the closet, leave two sets of shoe sizes on a pillow, and look after the child.
If Jason needed 20 minutes to get his bearings, shower, dress, and stage the scene, we are at 6h20m. That leaves 15 minutes to wash up in the backyard with the hose, overdose the child with adult cough medication, remove the diaper, block the child in the bathroom (where she left smeared footprints on the interior of the door), wash her clothes, dry her clothes,, put her in an unusual pair of shoes, put her in someone's bed ... and stage the scene.
Not everything that is being alleged could have happened in the allotted time. Only a family member would look after the child. Other than the father, there are no familial suspects ... so if someone looked after the child, it was the father, and therefore the father is the murderer. If the child was not looked after, then the murderer could be more random.
If the child had blood on her toes and on her pyjamas, then she was not cleaned up. Therefore, it is not necessarily true that her father is the only possible suspect.