I have been looking at pictures of the crib, and to be honest, I don't think the mattress IS set that high. Look at the black and white pic posted above. The top of the mattress would be right there where the bottom of the bumper pad is. I don't think it looks too high. When you look at the crib from other angles, I think it appears the mattress is set higher. But I think it is just from those certan angles.
If they had Lisa in a crib that had a mattress at the highest or close to the highest setting, then she would have been falling out of it every day, you would think. I just don't see them doing that. DB/JI may not be perfect, but I am giving them some credit as to not have their baby falling out of her crib repeatedly and doing nothing about it.
I am not sure what you are referring to as far as the car seat. I have only seen one picture of Lisa in a car seat, and she seemed large enough to be in a forward facing seat. I thought babies were supposed to be rear facing up to 20 pounds and then switched to the forward facing? It has been many years since I had an infant, but I seem to recall my kids were in the "toddler" type seats before they were one year.