No, by the way.
Or at least not necessarily.
Oddly enough I've seen more references to this from Bob's friends than from Brad's! Austrian economics is a broad set of ideas. Some of these ideas may have mislead Bob and others into 10 percent inflation predictions but there were a lot of other Austrians that were cautioning against forecasts like that.
Inflation predictions are more of a Rorschach test for how you think about the quantity theory than they are a test of Austrian economics.