Keep in mind the Spiderman suit may be relevant, and they're just saying it's not, to put a suspected offender at ease.
Police always have to keep operational matters private (so offenders etc don't know where they're looking, or how, and also to keep certain details private that would only be known to the offender), and rather than simply not saying they found it (which could still lead an offender to remain on high alert, wondering if they have found it and just aren't saying), to say they've found and discounted it would put the offender at ease, and complacency breeds mistakes.
All that being said, I doubt it's relevant, and any offender'd have to be pretty stupid to leave it lying around in a public park, better to burn it etc.
That's a worry about the man asking directions to Benaroon Drive, seems too much of a coincidence, unless of course it is used regularly as 4x4 access into the bush there, but were that the case you wouldn't think the police would've (seemingly) discounted the possibility of an opportunistic attack as they (seemingly) have, by virtue of the bush around the house and it being a cul de sac etc etc, as has been reported in MSM.
We know they've been looking at other avenues, but at the same time there's been an exceedingly strong focus on the search, despite a complete lack of the usual signs. I just hope having done so wasn't a massive mistake, ie that sufficient resources were dedicated to those other avenues which are seemingly more and more likely in the face of a complete lack of evidence of William having wandered off. I'd've thought the lack of scent found by the dogs beyond the yard would've been an almost sure sign he didn't wander, but maybe it's not 100% reliable.