How serious is it to be caught lying in a custody trail?

i think the major thing is how those things affect his ability to take care of the child. If he is lying about stuff that has nothing to do with the child and isnt about doing something that can send him to jail it wouldnt be as big as if the lies were about something that could hurt the child finalancial emotionally or physically. Although im not sure exactly what goes in with split custody its just a matter of what hes lying about