Videos failing to download to iPad from Canon Camera
I upgraded the iPad to IOS 9 Public Beta and did not turn iCloud on and the issue was solved.  This is not an ideal solution and I'm lucky that the Beta was available.

I tried reinstalling IOS 8.4 multiple times and the problem persisted. I tried both restoring the iPad from the cloud and starting fresh after an IOS 8.4 install.  Both of these failed.  I did not try a fresh install where I turned iCloud off from the start, however. I didn't think of this until I installed IOS 9 Beta.

I tried installing IOS 8.3, but could not get it to revert. I think Apple works hard to prevent this.

My conclusion is that there is a bug in IOS 8.4 that is causing this problem. If I had to guess, it has something to do with iCloud trying to sync huge videos from an external HD Camera. So perhaps it's an iCloud issue, but it's hard to separate the OS from the Cloud at this point. Hopefully the issue is solved with the IOS 9 Beta and continues to be solved when IOS 9 is released later this year.