You talk about a "historical precedent" that goes back to when India firmly identified itself as a socialist country. And from that distant, warped past, you fast forward 36 years to the present and to a country that in 1991 began its journey of economic liberation (which included jettisoning its socialist principles for all practical purposes), and expect us to believe that the two incidents are somehow related?
But what better examples to refute your ludicrous theory than Coca-Cola and IBM themselves, both of which came back to post-liberalization India. To the extent that India likely has IBM's largest global workforce [0], and Coca-Cola pours billions of dollars to maintain its leadership over Pepsi [1]
Surely those companies would know a thing or two about "historical precedents", don't you think?
As for the most likely reason behind this $5 billion figure (sorry conspiracy theorists, it isn't extortion either as Indian politicians know Google's power isn't something to be messed with in the age of social/Internet savvy voters) is the old-fashioned plant. I'm guessing Microsoft (the primary shadow-backer behind all anti-Google cases in India) laid out the worst-case scenario off-the-record to a PTI journalist, along with the $5 billion figure. And the journalist was either too lazy to question/research it, or too taken in (journalists like throwing up "exclusives" like this with billions of dollars in the headlines) to reduce it to the decidedly unsexy $~33M.
It's just a theory mind you, but having been a business journalist in India for nearly 6 years (and having done stories severely critical of Google, lest you think I'm a shill for them), I think it's much more likely than some of the other fantastic theories in this thread.
[0] http://www.computerworld.com/s/article/9234101/In_a_symbolic...
[1] http://www.businessweek.com/news/2012-09-11/coca-cola-masala...