Alright, lets try to get this straight. You are saying the skull dropped out or rolled out. I am saying the Le interviewed him 3 times to get the right answer according to them.
Under your scenario, if the skull rolled out or dropped out, then the mat that was attached to the hair that was attached to the duck tape that was attached to the skull, must have grown roots through it in 2.6 seconds. I do not see how it is possible that the skull was ever in a bag because of the roots growing through the hair mat. Can't have it both ways. Was the hair adhered to the ground or not? What she saw or reported on was something that was in a paper bag that had been transferred. She did not report the skull from the crime scene. IMO
Ps I am all for your scenario, the skull being in the bag, just makes it more look like it was put there later. The Skull being out of the bag and adhered to the ground, makes it look like it was put there sooner.
If it is true that the skull came rolling out, then someone is lying about it being adhered to the ground with roots. IMO