The TSA canine picks up on the scent of the boy and starts barking. In reality, the dog would notify the handler by sitting or laying down.
(At 1:15) Stabler says "How we doin?" to Melinda, but his lips appear to be saying something different.
In the opening scene, a nurse runs to assess the child, and then the bus driver yells out if anyone knows CPR. This seems like a stupid question, since the nurse is already with the child and would be trained in CPR. However, he asked for someone to *help* with CPR, so perhaps he knew CPR is tiring and she would need someone to trade out with.