"Always," he says.
He does, however, stop short of saying it is the most unusual case he has been involved in, although the statistics he has - based on data from hundreds of searches and some of the best analysis available - indicate the circumstances are rare.
The more than 100 people gathered for Saturday morning's briefing were told 50 per cent of Alzheimer's sufferers who wander-off are found within 800m from where they were last known to be, or 95 per cent within 8km. Fifty per cent are found no more than 15m off the track or route they would have been taking, or 95 per cent within 307m.
"They go until they get stuck," Mr Gordon said, "so search where someone could get stuck."
Delving into the thought pattern, he told searchers: "You don't know where you are, how you got there and what to do."
He put it into context when he told searchers the Trelinnoe Park gardens Mrs Wills helped her late husband John develop over the last 55 years on Old Taupo Coach Rd, about 6km east of State Highway 5, occupied 120,000sq m.
Moving that out to a radius of 5km, it was 80 million square metres, and if Mrs Wills was there she would occupy but one or two of them.
There was a gap of 5 per cent in all the statistics to account for what circumstances had not yet revealed and Mr Gordon said: "We know a whole lot about them but it doesn't mean we can always be successful in finding them."
"The jug," he said, echoing the common view that wherever that white plastic is, it is likely Mrs Wills is not far away.
Glenn McDonald from Rukumoana Rd, on the western side of SH5, was typical of those who went to help search. Trademark: shins and thighs scratched from searching through the blackberry and other growth on a heavily grown and rugged hill-country of the area.
And commitment: "We're virtually all part of the family around here. We all grew up together.
"It's just amazing how we can't find her here," he said, as he climbed out of a gorge he had just searched, having learned that even after a lifetime in the area there are still spots he never knew existed.
"Just to find nothing, with all that number of people searching. I know we are are looking everywhere, but how far would a 77-year-old go?"
Searchers included Land Sar personnel from as far as Turangi, Gisborne and Wairarapa, and Bruce Wills was pleased to have offered them the opportunity as an exercise and support for the movement, with specialists and local volunteers camping on-site.
It started with a briefing, including what for some would have been "gruesome" details of what they might see if they were to find Mrs Wills, but with instructions that whatever, they would "back off" to let the experts take over.
Having spent Saturday "waving my arms" and "riding in a helicopter all day" with local pilot Rick Graham, he ventured out through the bush and streams again yesterday, something he has done on countless days since he learned, while in Wellington, of his mother's disappearance.
Last night he was taking a practical approach, saying: "It was a good sort of closure when we finished-up with lunch. I think everyone went home well satisfied that everything reasonably possible had been done.
"We have to accept that, in this countryside, we may never resolve the mystery but I'll go to my grave knowing we did everything possible."
