I agree with your main idea, but if you think about it, the author isn't doing anything clever per se with Python. I mean, using numpy and associated libraries is fairly common when Python is used for numerical computing (remembering that Python is a _general purpose_ language, not particularly aimed at a particular domain).

I have tried Julia, and really like it, but am still using Python for most of my prototyping. Maybe I should force myself to use Julia for some time :)