Back to your wife's 1020. No DP you said, but is it a first hand 1020? I mean, if DP was installed once, a hard reset wouldn't erase it.
If not, then it seems that 1020 has received GDR1 and a Cyan update (a bit like the 930 did, at least in France, in October or November, I don't remember).
Is there any info about this "fake" Denim updates in any threads so i can read about this my self? the phone got the Cyan update when it rollout in Finland that must be months ago, and now this update? Is it suppose to be cyan update with some fix in the build? The phone feels much faster then before.
We are trialling an update to Lumia Cyan for Lumia 925 and Lumia 1020 smartphones in Finland which provides fixes & improvements ahead of the Lumia Denim update, which will be rolling out following partner testing and approvals.