I am seeing some weirdness with the Phone > Recents. My wife and I share an iCloud account for the purpose of sharing Contacts and Calendar entries. Since I upgraded her to iOS 8, we are seeing random Recents call activity in the Phone > Recents tab, and in the App Switcher > Recents, this random activity includes Contacts with whom we have texted. Not all of the recent contact activity is reflected, but both phones show some of the contact activity on the other's phone. Very strange.
I called Apple about it, and am working with a Senior Advisor to research the problem.