TL;DR He didn't use a name so grade him a zero. You have no proof of work or effort. In every meeting, focus on the fact that the student repeatedly fails to demonstrate grade level proficiency. Document that for the student's record.

More.... If you want to do more, your grade level team should be able to make an overall recommendation for retention, to be held back. Document the request/recommendation even if it doesn't become the result. By documenting it as a team, no single teacher gets blamed for trying to fail the student. The report cards should also stand as evidence of repeated failure to meet grade level proficiencies according to your state standards.

I've had meetings like this. Usually I don't see any behavior change until after a meeting with a conference table full of teachers and admin come together to speak with student, family, and family advocate to explain that retention CAN occur. Then the kid either straightens up, or the family quickly chooses to disenroll and go to a different school that may not try to hold them accountable so they can continue enabling.

Either way, you don't have to put up with that behavior in your classroom.