video deleted from iPhone 5s appears in iMovie import window
I have an iPhone 5s running iOS 8 (latest update). There are about 8 videos I've made and subsequently deleted over the last nine months. They do not appear in Photos (or in Videos) on the iPhone. They are not offered as downloadable when connected to the iMac with iPhoto running. However, if I connect the phone to the iMac with the iMovie application open (on the iMac, running Yosemite), then iMovie offers to import all of these supposedly deleted videos! When I import them, iMovie does not offer to delete them. I just want to reclaim whatever space is being taken up by these.
I have tried resetting the iPhone to factory settings, but when it syncs with iTunes and restores from backup, the videos return. How do I delete these videos?! Anyone?
iPhone 5s, iOS 8.1.3, null