You’re looking for an exclusionary rule that applies against the defendant.
There are a few rules (privelege and some public policy-based rules–I’ve got an idea about a case in which I was involved) like that and also some events (like failure to give notice of an affirmative defense) that could qualify. I’ll poke around and see what I can find after I finish doing homework with my daughter.
Weird. They must have changed something over there. I almost never have to give a login for that site, even on a borrowed computer.