Short version:
You lost the flip!
Long version:
These conspiracies theories are inexistent.
Duplicate works exactly like many other chance features in the game (ie Mindbar).
Here is a page to test your theories:
http://s2.piratesglory.com/dice.phpPretend you are going to cast Duplicate every time you click Roll Again.
For any number of 50 or more, Duplicate is successful. For any number less than 50, duplicate fails.