I posted this image earlier in the thread, it shows that the safety is not quite aligned with the slot it is supposed to fit in to meaning the bolt handle must be up in the "fully up" position.

The images of Day picking the rifle up in no way demonstrates the bolt handle is not fully up, if anything it's quite the reverse.
The bolt handle is clearly sticking up, there can be no doubt about that. That the safety is not aligned with its slot means the bolt handle is fully up and that the bolt is not fully forward.
If, after the last shot, the bolt is pushed forward in the usual quick and fluid fashion, the bolt would be fully forward so the bolt handle would have no problem latching downwards with the bolt handle fitting snugly against the body of the rifle.
The best explanation for the position of the bolt in the Alyea footage is that the bolt is jammed. What would cause this?
Walt's explanation, that the ejector has not properly engaged with the bullet and is jammed up against it, seems most plausible. This would account for the very small misalignment.
But what would cause the ejector not to engage with the bullet? Normal use?
Or manually inserting a single bullet into the chamber?
I posted this image earlier in the thread, it shows that the safety is not quite aligned with the slot it is supposed to fit in to meaning the bolt handle must be up in the "fully up" position.That image appears to me to be made after Fritz ejected the cartridge. So, it appears to me to be irrelevant. Also, if it were shown to be relevant, if the camera isn’t at a perfect 90-degree angle and aligned perfectly with the safety, then the angle involved will affect how the alignment with the wooden slot appears. This is because the wooden slot is closer to the camera than the metal safety.
The best explanation for the position of the bolt in the Alyea footage is that the bolt is jammed.No it is not. There could be several other better explanations, including that it wasn’t pushed down by the gunman, that it was pushed upwards when lowered in between the boxes, that Day pushed it up while examining the knob for prints before he lifted the rifle off the floor, etc.. Also, if Walt’s theory were true, gravity (with the muzzle is pointing toward the floor) and friction would have held the cartridge in the barrel when Fritz pulled the bolt back. Therefore it would not have fallen to the floor.