Sounds like quite a pickle. I have heard of dogs rolling over on the pups and accidentally killing them. Of course, I have also heard of dog killing all the pups on purpose too...
I really don't know what advice to give you. I think the ball is in your neighbor's court. They will have to make sure mom and pups are looked after properly. I would just encourage them to get them all to the vet ASAP, especially considering the situation with the daddy dog being so much bigger. How big are the pups in proportion to the mom? I would just be afraid that her giving birth to bigger pups may have damaged her on the inside somehow...torn uterus? Internal bleeding?