I'm sorry that you've had to meet with so much unnecessary anger and assumptions OP.
I don't understand why people seem to think she has a hidden agenda
. And no, I don't think she is trying to manage his legal case - where have people even got that from?
And why is it relevant whether he will be at the birth?
Clearly, he has asked for advice (as family members do) and she does not know much about this issue (understandably - her main experiences of separation (her parents) are from 1992) and doesn't want to be misinformed, so came to a parenting forum (the perfect place) for advice.
OP, how tough for him
. And whilst I do know a few families with a 50/50 split (both 1-week-on 1-week-off and split weeks) they all have older children (aged between 7 and 15) where the parents have split up after the children were born. Unfortunately, in most cases, the mum has more custody, usually with the dad having every other weekend and holiday time.
I'm not saying he can't get 50/50 but it is unlikely and he will have to fight quite hard.
Best of luck to him, and the child is lucky t have 2 parents who care for him so much.