Your friend sounds like a respectable guy to standby the girlfirend and her baby (even if the father is questionable).
Either way, for people going "oh, my snake is going to eat the baby', around 20 children are killed by dogs every year. I don't see many families getting rid of the family dog... A constrictor snake related death is about 5 every couple years. (emphasis on coupe years) And that's usually due to incorrect caging like using a weight to lock a screen top. All of these deaths are preventable with correct caging and security.