Animation in DAZ is very much hit and miss. iRay rendering times are pretty insane, there's no reliable in-editor preview (you can press "play", but it runs at seconds per frame, making timing and continuity hard to track). And a single bad frame can ruin a shot, forcing you to re-render large chunks.
Having said that, I've never managed to screw up *quite* this badly before. 18 hours worth of rendering, down the drain. It's enough that I went back to fix up my workflow. I'll talk a little more about that later. For now, enjoy this epic fail.