There is a message on the edit screens which acknowledges the bug. Here is the quote:
Expect edit conflicts. Due to a bug on the new software, edit conflicts will overwrite other people's changes, even if you do not save on the edit conflicts screen, and even if you were editing a different section. As a courtesy, take a look at the edit history after saving and fix any accidental text deletion or duplication.
This is pretty serious. They should roll back to the previous version. -- Silverback