When was the photo taken of the bones inside of the eliminator? I wonder if DM didn't dispose of LB in two separate firings, and the second firing didn't complete. It seems odd that the bones found in the photo were the arm bones. I would expect that the larger femer bones would be present, but they weren't.
DM sent a msg asking how long the firing would take. I expect that he gave it the required amount of time and then walked away from it. He wouldn't open it up to check.JMO
To be brutally honest, the way they rolled her up "like a spliff" and the fact that she would have been stiff as a board by the time they got around to burning her, I can only guess that they put the spliff in feet first and just kept pushing her in until the could close the door. This might explain why the burn wasn't completed.