Do not worry, i am with your hubby when he said she laid on it, i just and am still on puppy watch my guys are 3 weeks old today, she had 8 one died at birth and she laid on 2 more. I am not working right now or else i probably would have lost the whole litter, I found my female being a first time mom was sitting up to nurse and then gets all the pups under nursing and then sits there for a bit and then gets tired and lays down on top of them all. With mastiffs being the size they are its hard for a little pup to move after it gets the moms full weight on it, cant breath cant scream cant move. I also had one pup that was just under a pound at 15 oz and did not grow at all, he only gained a 1 oz over the course of two weeks until he just died. My litter also got over fed by the mom, which never in my life have i ever heard of such a thing, their poops started to look like curdled milk, so went to the vet and that is what she found out after talking to other vets with more puppy eperience. So i had to keep the mom away from her pups and only take her into feed them and clean them and then get her out, ask me how fun that is, NOT lol until the poops started to look normal, their little systems were working over time trying to digest the extra milk it just basicaly shuts down and the pup dies from starvation even if it is nursing.
Also newborn pups up to the age of 2 weeks i think it is , can not regulate their body temp, the can not shiver, the mom normally keeps this regulated but if mom can not be present the box must be kept warm, even if the room feels warm the floor of the box may not be, put your hands down at the floor level where they are and make sure it is warm, i find a heat lamp to be the best as a heating pad can cook little pups if the pup gets to warm and cant get away from the heat to cool off, being to warm is just as bad as being to cold. If a pup gets cold it will also slow down digestion, so if a pup gets cold warm it up first before trying to feed it. A heat lamp can be raised if to hot or lowered if to cold, pups should not huddle that means they are cold, they should lay beside each other but not all piled on top of each other.
All my previous litters have been text book, no issues, this is my first female that i have had that has squished pups and i have never had a fading puppy either, that is what they are called when they are born nice and healthy and just seem to fade away after a few days to a couple weeks. So i wouldnt worry to much, just make sure they are warm and make sure the mom has enough space to get away from the pups to lay down so she doesnt accidently lay on them. And dont forget to make sure mom gets extra food and water cause it takes alot to make milk and she will get real skinny if your dont up her intake, my female is only feeding 4 and she has lost alot of weight even after switching to a higher protein and fat content food.
So dont panic, just keep an extra eye on her when home to see how she acts with her pups, that will give you a better idea if you think she is making them to wet or not