I haven't followed everything in this case, but I did watch the video. I find it hard to believe. Stop and think about this for a minute! If you are about to throw your baby off of a bridge at 3 in the morning and you hear a car coming, are you going to turn and look that person in the eye????? Or are you going to lay down on the ground and try to hide yourself???? A person could very easily crouch down behind the guardrail between the pavement and the walkway. Makes for a good story, but I'm very suspicious.
I think the detail of looking right into the eyes is designed to accomplish one thing: to implicate the mother. There were media reports that there was a dust-up between the families at the hospital so a tip trying to pull her into this mess wouldn't surprise me.
That said, LE should at least investigate.
JMO