I'm having a similar or the same problem, you are not the only one, jut one question, how long is the video?
I'm having this problem with a 45 minutes video, browsing the web I found more people with similar problems with long videos. for all the people trying to help I'll try to describe the problem. the video was shot with the camera app, it appears on Photos and on the videos album, I can watch the video, I looked on Icloud to see if it was there but no. the problem is that wen you connect the iPad to the PC as a camera, ALL other photos and videos ARE there EXCEPT for the one video, is like a ghost video that only appears on the Ipad.
Any suggestions?