I believe they mean that, if bitcoin strongly succeeds somewhere, the current currency in use there would be replaced, and as consequence it would lose value, making all prices quoted on it to go up.
It would only cause hyperinflation like that if bitcoins adoption grows really fast in that nation, what I find very unlikely.
IMO if bitcoin succeeds bitcoin adaption will grow very fast. Once bitcoin becomes something acceptable to the general public there will be a breakthrough. When people see bitcoin gainign value versus fiat currencies, and there's no trust problems holding them back, they will sell fiat currencies. Which will accelerate the inflation of fiat currencies, which will provide a stronger incentive to keep your saving in bitcoins instead of fiat currencies, in turn accelerate fiat currency inflation. This is a positive feedback loop. Self-reinforcing. Self-accelerating. I wouldn't give the fiat currencies more than a few days once it starts.
Philipp
A maximum of 21 million bitcoins minus the estimated 500,000 to 750,000 stolen. That 21 million has to cover an expansive population of 300 million in just the United States alone. Good luck with that.