Maybe the producers are making political points ?
The 2nd URL link points out that the book is written in 1996, and the producers related their show to US presidential administrations that did not yet exist at publishing time.
well I went back and checked again and must admit I was mistaken. The tanks can only pull back from a blitz, which I guess has always been the rule. My bad. Anyway, having played with that rule for a few games of the kind described above, I still say it makes for a very interesting match. Germany benefits, but so does Russia since Russia gets to use her tanks more often.