I think there may be a cover-up here.
Corrie Mckeague: Evidence 'manipulated', mother claims - BBC News
I hadn't realised that mum is a serving police officer in Scotland and has picked out an anomaly in the evidence regarding the weights of the refuse bins picked up at the scene.
As his mobile phone signal followed the path of the truck back to the dump I feel it reasonable to surmise he was in that vehicle. If the crew saw his body and panicked they may be hiding the truth of what they did next - even though it wasn't their fault. You and I would have called for an ambulance but others may have felt they were to blame and tried to get rid of evidence.
I hope Mrs Urquhart and family can get to the truth.