One thing pugs as a breed are NOT is mean. There are bad eggs, I'm sure, but they are VERY sweet, loveable dogs in general.
I read the quote on that website...disgusting.

I can see how the lab puppy could have done that, if the swing was open on the side for the baby's legs or if it was a car-seat type swing. It wouldn't have been necesary to knock the baby out of the swing if that's what actually happened.
Shame on the parents - if that is the case they should be charged with child abuse/neglect and animal abuse.
I do feel bad for the parents because regardless of how good of a parent one is, there can't be much worse than losing your baby. But I do believe that they are responsible.
Yes, all parents leave their babies alone at some point. But NOT for an hour and a half without checking on them and NOT in a swing with 2 dogs in the room. They were in the wrong, and that poor baby and dog had to pay the price. and if that's actually what happened, there's NO WAY they didnt hear that screaming if they were in the next room - or even the same HOUSE - as that child.