You're just misunderstanding how biohazard works. It states that when the opponent is struck that they have a percentage chance to deal out a debuff, not when contact is made. So both non-contact and contact hits have a chance of triggering the node.
Sorry OP you didn't find a loophole for some nodes that have been there for years and forced people to rank numerous immunity champs.
@Miervo if it makes you feel any better, you’re not the first who’ve misread that interaction.
Non contacts do not bypass biohazard, it has never worked like that