Since reading more about corries personal life, I had thought that maybe he had gone into the HS area to meet someone, but there are so many ifs and buts about that and seeming as the police have made such a mess of the biggest line of inquiry so far, you cant trrust any of what they have said so far or anything else that has been said.
But - I have a feeling this could have been a tragic, tragic accident, maybe Corrie went into the HS area for a wee, maybe he was going to phone a pal for a lift home, and put the phone on the edge of the bin whilst he wee'd, maybe the phone fell into the bin and corrie felt he was able to go in after it, maybe fainting from the going head over in to the bin + alcohol, or hitting his head and knocking him unconscious - regarding Biffa, sounds like an overall lack of competence, staff not knowing or being trained in to how to interpret data regarding weight/load/material, bin men, not giving a damn how heavy the load or what they were collecting as long as its job done with no complaints then they have no bother from the bosses
I also think if there was foul play and the police could be trusted on their investigation to date, then we would not be having such a varied debate on what happened, I am sad to say that maybe we wont really know for certain what happened, why and if anyone else was involved