If it had been the baby being baptized, obviously she would have had to stay. But I agree with you that one of the adults should have taken her out, especially with CCTV set up. I think it would have been fine for an usher to approach them and ask that they take the baby out for at least the duration of the ceremony.
Pod. Our church doesn't have a cctv but they do have the priest's microphone wired such that you can hear her over a PA system in the hallway and in the nursery. The little ones stay in the nursery until after the exchange of the peace and then are brought in but if your child needs to be removed you can still hear what's going on in the nursery.
When there's a baptism they bring the kids participating in Children's Chapel and the nursery back in so all of the congregation is present for it, but if your child's not the one baptized and is kicking up a fuss, they would rather you take your infant/toddler out than disturb the service. Our church is pretty tolerant to kid noises during Rite II as it's a more family-oriented service as opposed to Rite I which is earlier and more adult focused. If your toddler is quietly babbling or giggling, or asking questions about the service, few people mind.
When it's someone new that comes in with a small child the typical MO is "Oh just to let you know, we have a nursery here for little ones and you'd still be able to hear the service!"
My youngest behaves better when his older brothers are not in the pew. Yesterday they were acolytes and singing in the choir so Piratebabe was relatively quiet.