Wow. Just wow.
Asking Ioan on the wizard if visitation would happen the following day is the equivalent of Alice saying "want more?"
There would have been a strategic reason why Ioan accepted the sudden offer of an overnight visit. If it had been court ordered and if it had genuinely been to advance and promote his contact with the girls, I would have expected Bianca to have made herself scarce for the night, and for her introduction to the girls to be more gradual. I think his legal advice would have been to accept it, have an expert psychologist chaperone and for Bianca to be present. The hearings are really close. Evidence was gathered (though far more traumatic than was probably anticipated), and Ioan has given Alice enough rope with which to hang herself.
It is likely that a full psychological evaluation of the girls would take time and potentially cause a delay to the custody hearing. Good experts are backed up for months with work, the last thing he wants is someone conveniently "available" in case they are not very good. I would suggest that if the expert evaluation is to happen, and if it would cause delay, that the girls should be removed from Alice while this happens. Both girls are suffering significant emotional harm which is likely to impact on their mental health for the rest of their lives. If the court is unwilling to do this, there is no solution and Ioan is fighting a losing battle, because even if he wins custody, the arrangement would fail very quickly because of how damaged the girls are especially Ella.
Just my opinion.