I haven't seen that in a while but I did read it.
I think it comes back to semantics actually....
what is inflation? Mises has a whole write up where he says inflation isn't clearly defined and if, IF we're going to use the term the only sensible definition is "money supply inflation ABOVE the increase in demand for money"
So according to Mises, supply inflation that tracks with the increase in demand isn't "inflation" at all.