Downloaded videos permanently marked despite download failing

I wanted to do a bulk download of some event videos. So chose 50, that failed after about 10 minutes. Tried other amounts and soon discovered that any combination of events led to a 'network error' when downloading. Internet is fine, have 150 meg line and works fine. I can download individually without fail but now since I selected those first 50, it now  marks them as permanently downloaded, with no further possibility to mark or clear that status, despite the download failing. Seems a huge mess. Why are the multiple downloads constantly failing? How can I clear this status on the events and try again another day?