Since we are only grasping at straws just to know what was found, drawing reliable inferences using such a complete lack of knowledge is going to be impossible, sad to say.
We know the bucket contained something, and the implication was offered that it was case-related stuff (which rules out the idea it was left there by a different party), but we don't know what stuff that might be. We know it wasn't big enough to have ever contained all the remains at once, only a 2 gallon bucket, but there are lots of things (or collections) smaller than 2 gallons.
Did the bucket have a lid? Was it on the bucket when first found? Did it have any markings, or identifiers of any sort? Was anything written on it? We don't have a clue.
Was the bucket used as a depository of personal effects or maybe even something more ghastly, such as body parts? What was or wasn't in it tells part of the story, but we don't know that either.
It's certainly possible that Holly's body was dumped there at some point, or maybe it was tossed, or maybe it was carefully placed there. Or it may have been atop the ground, or it may have been hurriedly buried in a shallow grave. The condition of the remains, and what detritus was on them, probably tells the story of how the remains were originally situated and whether or not that changed due to nature, and may tell it clearly, but we aren't owners of that info.
Was she hurriedly buried at this place soon after her demise, but not deep enough, and over time due to the elements it worked its way to the surface? Again, there's forensic evidence that probably answers those questions, but we don't have it, so no way to know if she was or wasn't buried, and no way to know what inferences we can then derive.
The excavation they did probably revealed stuff, perhaps forensics told how long her remains were sitting there exposed which would gives some clues as to how she might have come to be there, and maybe even provide clues of whether she had been moved once or more after her demise. No doubt LE examined all that, but we've no idea what it told.
But without the info that LE has, the variations are so numerous that there's no way to even begin to tell the story, other than by making up whatever we want to make up. LE may know a lot, but we have no info to work from apart from our own biases.
