The proposed repeal was dangerous, Busch said.
After a review of the Bristol case by retired chief justice Sir Ronald Davison, the risk assessment put parental violence "centre stage" in custody matters. But the Law Society supports repealing that assessment.
"How many more kids do we need to die before we again see that there's a co-occurrence between spousal violence and child violence?" said Busch.
Although the bill makes child safety paramount in Family Court decisions, Busch said parental contact and access to children often trumped safety concerns.
In Alan Bristol's case, said Busch, "no matter what he did, the judges never saw him as dangerous because he presented so well. His class and his handsomeness masked his dangerousness."
But Law Society family law section chairman Garry Collin said Davison's main recommendation - that child safety be paramount - was a first principle in the bill.
Busch, Collin and even Family Court judges agree that the bill, if passed, could put New Zealand in breach of the UN's child rights convention, despite Government assurances to the contrary.
In their submission on the proposals, the Family Court Judges of New Zealand said the lack of opportunity for a child (or the child's representative) to express views in the proposed new Family Dispute Resolution process could conflict with the Care of Children Act and New Zealand's obligations under the UN convention.
During the bill's first reading, the government said it would save time and money in resolving family justice issues.
Justice Minister Judith Collins told the Herald on Sunday it aimed to ensure the court focused to keeping the child safe, rather than the current focus on whether an allegation of physical or sexual violence was proven or not.
She said she would carefully consider the concerns raised about that proposed change.
The Attorney General's report on the bill had found it did not breach the UN convention.
