I've made a very basic plnkr to make this easy to test: http://plnkr.co/edit/PWh57DPNuks7rA5oI7r4
To reproduce, do:
-
Select editor contents with ctrl-a and copy it to clipboard with ctrl-c.

-
Press ctrl-v to overwrite current selection. This will erase the ng-model contents, but in editor, everything looks all-right:

Tested on Ubuntu with Firefox 55.0.2 and Chromium 60.0.3112.78