Exporting issue

I had made a video featuring a few different clips and a song in the foreground. I detached all the sound from the video clips (it was a sports highlight montage, so the sound featured crowd noise and color commentary). The video plays fine until I export it to the camera roll. Once it makes a copy and I play it from my photo album. The first 10 seconds features audio from a clip that I did not even use in my compilation. I mean, I used part of that clip, but not where that audio is played back. Is there a way to correct this? It's really confusing.