Argh I was about to say one thing I couldn't see was the big blue plastic box NM referred to and that maybe they'd thrown toys from the garden on top.... then I remembered it had all been moved to the shed by the time these pics were taken.
Maybe to avoid police seeing that they'd moved some large items out of the lounge since they last visited, they did put in toys from outside in place of what had been moved? Not that I think police would have noticed, but NM wouldnt know that and th elast thing he'd want to hear would be "Wheres that big blue box gone that was here before?"
ETA, Id I'd have read on I'd have seen we're all on the same page about the stuff already being moved etc. lol
I think he was frantic. He knew police would be coming round to search. They asked the police, when Becky was reported missing, what the next steps would be in the search for her. He had to know a routine search would be done at CML because they were last people to "hear" if not see Becky. It makes perfect sense to me that the garden clutter was brought into the house in case CML was searched before he/they got rid of the evidence. At that point, police would be looking for a missing child hiding somewhere - not a dismembered body.