Maybe there's the proverbial grain of truth in that story, but I would think, if so, it's really small one.
As it seems, this achievement was published by just a single newspaper and not even a German one.
So, I would think, that the results weren't as sensational, as written.
To me, the most probable interpretation is that given with "A small test rocket, 15 feet tall with a motor
of 440 pounds thrust, was to be built and launched first...." on that´site.
With a great probability a greater success would have been reported in Germany, too, especially as
serious German interest in the development of military rockets principally started not before 1935 with
the foundation of the project department led by Walter Dornberger. Before that, large rockets weren't
regarded as really worthwhile, so there would have been no need for much secrecy.