There is a big spurious gap in the info/truth about the bin-lorry/landfill thing IMO. Take your pick at which part really, but I'm here to mention something about the actual landfill part.
And that is that, the bin-lorry that picked up the bin, would not have directly dumped it's load onto the landfill site.
Landfill site's all use specialist vehicles for the job. You can Google map any LF site in the UK, including Milton, and you will see only a specific type of vehicle enters the actual landfil site and does the dumping. You won't see any standard bin-lorries on the landfill part of the site itself.
Therefore, there is a transfer process at some point between the collection (of the bin) and the waste being dumped onto the actual ground (landfill). It would go bin lorry with waste content to landfill site -> waste content transfer into container/specialist landfill vehicle -> dumping.
As you see in the picture above, that specialist vehicle seems to utilize "capsules", that it can pick up, change at whim etc. There's also the flatbed tipper trucks, which seem to be used at Milton perhaps more than the one in the image above.
I worked on a landfill site for about 4 months. I only ever saw the vehicles pictured above and bulldozer's on the actual landfill part of a landfill site. I admit I don't recall very well how the transfer from standard bin lorry to the larger vehicles occurred. But I do remember there being strict protocols about who and what goes past a certain point, onto the landfill site. I don't think it included street bin lorries. And it makes sense. Biffa, Grundon, whomever, don't want their expensive street lorries careening down the side of a landfill.
So. The first major misconception is that a standard bin lorry (the one that entered the horse shoe) later tipped its load directly onto a landfill site. I don't buy it... At the very best, the Biffa lorry dumped its waste into a container near the front of the landfill site (again, you can see many containers at the front of the site on Google maps). A second vehicle like the one above or a flatbed specialist truck would've taken it out onto the site.
Is this significant? Possibly not. But it raises the question of the vagueness of certain assertions, yet again.
But the second misconception, which is more of a personal grievance from my time and observations working on a landfill, perhaps is. And that is that dumping onto a landfill site is not a "willy nilly" event. You don't drive in and dump it where you want, the workers do not do that. They will likely have been using a particular zone or quadrant of the landfill on the date in question.
They should be able to look at their log and narrow down the quadrant that was being dropped into on Corrie's dates. I don't know how refined (metres squared etc) you can get with that, but I'm almost certain logged quadrants exist in some form on landfill sites. It's how they allow for others areas of the site to regenerate.
This I feel is significant, because when they say "searching landfill" it gives the impression that the whole site needs to be searched, when in fact that probably isn't the case at all. Much like the Biffa logging its (incorrect) weight, someone at landfill will have had to log, in some manner, even the most basic, their duty of taking the transferred waste from container to the dumping spot, even if that is just "Quadrant: Answer. Date: Answer. Time: Answer."
And with that in mind he probably should've been found by now, and if not, probably never will be. But I believe that would be because he isn't there, not because there is "so much waste". IF they do come back with this sort of statement, that he couldn't be found and they feel he is there, but perhaps under "too much waste" to reasonably search, you know it's probably BS. Because they could probably hone in on a particular zone and dig 100 feet if they needed to.
EDIT. Whilst the bin lorry may have turned up and put waste in a container on a Sunday (can't quite remember the actual day it was supposed to arrive, I think it's Sunday though), that container wouldn't have been moved on the Sunday, surely. Whilst that container may have had several loads put into it (if various bin-lorries did a similar thing), again it would possibly be logged, it could be searched itself for traces. And it allows for an extra period of time where an early/initial discovery could have perhaps been made (though I acknowledge it's reasonable that such a discovery could also have been very unlikely). That said, the "log" we've heard about could very well be that, the weight test conducted on the landfill site when bin-lorry transferred its waste.
And there's one final thing, and that is that after every single other co-incidence that occurred from the minute Corrie walked into the horseshoe up until this point, like no witnesses, no cctv, no phone discovery, the final blow would be that the guy driving the bulldozer who basically does the "flattening out" of dumped waste didn't get a hint at anything. I won't describe it in detail, but I'm sure you can understand how, you might expect him to notice something. He spends all day every day seeing, smelling, pushing standard waste around, his trained eyes, nose, ears... will spot an arm, a leg... But no-one ever did. The Biffa never got a hint of a person. The period Corrie would've been in transfer, again not spotted. The point of waste dumping and the bulldozer flattening, not a hint. These things still arguably point to it never occurring at all.
One last thing. The found a back of a phone once, in January 2017. The same month where they said they wouldn't search the landfill (oh how things changed eh!). In the article it says the police effectively dismissed the back of the phone and wouldn't do any further testing on it (though it was never so clear what tests were run). But again, it makes you wonder -- even the most junior of SOCO staff could do a fingerprint swab of that phone case, to at least confirm it perhaps was or wasn't his. But they never did.... it boggles the mind?