I’m not sure how Saverin renouncing his citizenship prevents a tax liability in the first place.
Here’s a post from the Hotair website for your consideration:
Saverin owes no tax on his Facebook shares until he sells any shares.
In fact he never has to pay any tax on it he so chooses. He can borrow against it to the tune of millions a year and then write off the interest charge against other income.
It is a method used by all the Warren Buffett’s of the world so they pay less tax than the paperboy.
For this you can thank the Congress for writing a 78,000 page tax code. Saverin leaving has nothing to do with taxes.