Unless Nikon are completely inept there will be months and months of sales calcs and profit forecasts carried out and reviewed from low to high level. There's no way a nigh on 10% discrepancy could slip through. I just don't buy it
I disagree at the end of the day and I have a fair amount of insight into how this works so I think I'm right.
I work for a company which sells it's products and services globally and I know first hand how much trouble it is ensuring no mistakes are made. We are paranoid about exchange rate freshness, tax calculations and the like and even so we loose a notable chunk of cash every year in slip ups. We have some serious automated analysis for anomalies and report weekly but we've missed mistakes for a couple of weeks before. I would assume that Nikon don't have our levels of central control or systems integration (we're a technology company, our data mining and analysis is in a different league).
Basically, my experience tells me the mistake is plausible - if the mistake was made initially it'd be next to impossible to spot a mistake in one countries pricing before you started actually selling (doubly difficult for preorders where the accounting is theoretical until the physical product turns up) then after you did you'd need to wait for reporting from resellers, then reporting to head office and somebody to pick it up (and it's grunt work running the numbers so it'd be somebody junior, so it'd need to go a few levels up the chain and be rerun before it got flagged as a real issue).
Given that, a couple of weeks after presales started seems a pretty quick spot to me - we're paranoid about it happening and are in a better position than Nikon (no resellers to worry about, all accounting centralised so no country reporting etc) and we've missed bigger mistakes for longer.
There's a degree of ineptitude as most of these mistakes are made during the lifecycle with price changes and tax changes etc rather than during initial pricing.
But it's easy for it to go unnoticed in projections before sale, it's a spreadsheet full of fairly abstract numbers somebody is looking at, a 10% error easily disappears in there.
Big companies regularly loose lots of money on stuff like this because everybody thinks somebody else will know about it and it takes time to get picked up as a mistake as a result.
Anyway, my experience is it's a plausible mistake and there's no reason to lie about it if it is a price rise.