Test application demonstrating the issue can be found here

Steps to reproduce:

• navigate to a page while using clearHistory="false" in the HTML
  e.g.

<!-- Setting clearHistory="false" via HTML is causing clearHistory to be TRUE -->
<Label [nsRouterLink]="['/item', item.id]" clearHistory="false" [text]="item.name"></Label>

• return back using the hardware back button

Result: the app is exiting (if using the test application) instead of returning to the main page.