>BTW, my colleague solved the issue by switching to ng-if instead of ng-show for these two elements. Of course, it doesn't explain the Google Chrome ng-dirty bug, but it does solve that problem. And it's the second time this week he solved problem by implementing ng-if.
>
>https://stackoverflow.com/questions/19177732/what-is-the-difference-between-ng-if-and-ng-show-ng-hide#_=_

As mentioned in an earlier reply : ng-show merely hides or shows the element - it's not removed from the DOM.
ng-if removes or adds the element. I'd guess that with the data source changed and that, with ng-show that caused the ng-dirty to be set. With ng-if the element was created after the data was set so it would still be ng-pristine ?