Instead of the claim of "I can easily get to twice £X million" -- in revenue? profit? valuation? -- it looks like the author's RoomScan app is near-moribund. RoomScan Pro, which sells for $4.99, hasn't been updated in over half a year and is listed as "optimized for iPhone 5." It's been mentioned in only two articles indexed by Google News in the last eight months. The Roomscan Twitter account hasn't been updated since November. The free version of the app has been updated more recently, but free in this context isn't exactly going to pay the bills.
These are not the signs of an app that is getting to "twice £X million" anytime soon.
I do think it's an innovative idea and a good implementation, but as we see on HN all too frequently, not all innovative ideas and good implementations amount to a "twice £X million" valuation. Any company (or product) is only worth what the market will pay.
As for Google, I don't know how their corpdev team works, but my rule of thumb after working at some very large companies is: don't attribute to malice what can be explained by bureaucracy. It's not unusual for different teams not to know what the other is doing, even when they should. I don't see anything that justifies speculating about nonexistent employees named Maxine, and that kind of bizarre speculation likely poisoned the discussion.
Whoops.