[jabbywocker]

You aren’t refuting a negative because the statement isn’t “they are unrelated” the statement is “(with current information) there is nothing suggesting they are related”

If you’re close to the situation, and have a substantiated reason to believe the claim that there’s no current information suggesting they’re related is inaccurate, you should be able to back that up. Except we both know you can’t, because you’re attempting to refute something that wasn’t actually said.