There have been at least 6 Deathclaw attacks that I've survived with no casualties that did not count toward this objective. Meaning I have fulfilled the requirements for this objective at least a dozen times, but I'm still sitting at 6/7 completed.

I'm on version 1.2.1 on an iPhone 6+ running iOS 9.0.2. The app was originally installed with version 1.1, and has been subsequently upgraded to 1.2 and 1.2.1 by way of the auto-update feature.