I'm not sure exactly why George bulldozed the hole so soon after being told not to. It is theoretically possible that he was trying to hide something or could he have been trying to hide the absence of something (or someone). Then again he could have been so grief stricken that he needed to move on with life. I cant imagine the grief that must have accompanied that day for the Sodders.
Here's a huge sticking point for me. "Chief" Morris is said to have planted the box with the tissue in the hole during the time span that the hole was opened (4 days). How did he do this without being caught? It was said that family stayed there on site until a new structure was built (did they stay in the garage? temporary shelter?). Additionally, Morris claimed he used a wooden box he found at the Sodder's to bury the found tissue. How did he do it? Again, this detail (like many others surrounding this case), seems improbable.
Im guessing Morris did not do it the day of the fire. There were a LOT of people milling around the day of the fire additionally he is the acting fire chief. He would (should) have had a lot of responsibilities that day. How would he have had time to sneak away to get a wooden box from the Sodders, somehow get his hands on the beef tissue, secure the box, climb down into the hole then place it in the hole under debris without being seen.
Did he sneak there under cover of darkness to complete the mission? Did he wait until everyone left? If you look at the layout of the yard, I think it would have been somewhat difficult (or at least not easy) to just drive up, toss the box in and get away. Furthermore, if we assume George didnt tell anyone he was going to bulldoze the hole, how did Morris do it in the span of 4 days? Additionally, there were probably onlookers, rubber neckers, etc. around for the following days.
So if he didnt place the box while it was open, it would have been much more difficult once dirt was in place. And at that point, why bother? He could not have known George would eventually dig it up.