IIRC, it was the uncle who said the paramedics were concerned/ suspicious about the first incident, although he finished by saying the family wasn't worried. My interpretation of this statement is that at least some members of the family was definitely suspicious about a healthy active child suddenly having this "seizure" especially if they are observing the mother becoming more detached from the child. Even if the paramedics were suspicious, they wouldn't be confiding in a family member - maybe the paramedics who hadn't seen this child before, and had no context for the incident did NOT see it as abuse. But at least some family members were suspicious, and probably never believed the abduction story.
If someone called the ambulance because the baby was unresponsive or not breathing, and then the baby had recovered by the time the ambulance arrived, the paramedics would not necessarily recognize abuse, especially if there were no bruises or any signs of distress. They would probably have recommended that the mother see the regular GP to look into possible causes for the incident. The family members who had seen the child before, during and after the incident would have had a better perspective.