To be honest, I'm not sure if it is reproducible or not as I haven't gone back and tried to re-render any of the scenes that failed.
However, the last three errors I received that caused the render to stop short I simply re-rendered the scene from the frame in which it left off at.
The very last scene I rendered didn't fail but the previous two did.
However, I'm definitely more than happy to send the scene file to you. What's the best way in which to go about doing this?