It's not really a massive issue though is it? You can just get an app to stitch them all together if you want a full hours worth of footage or tell your media player to just continue to the next file? I can see why they are short clips (60 seconds), it's because it would take too long to download a 1 hour clip if you're doing it over wireless.
For your comment about some clips only being 15 seconds long, I would guess taht the shock sensor went off and the rest of the footage is under that section rather than the continuous mode.