Plaintiff: "There was a dead-body in the toilet, but the defendant has been regularly flushing, thereby destroying the evidence and proving his guilt."
I was referring specifically to civil matters, not criminal ones. A relevant example would be a claim that D defrauded P; a finding that D intentionally destroyed evidence that would prove the fraud could be used to support a finding of fact that the fraud occurred.
Plaintiff: "There was a dead-body in the toilet, but the defendant has been regularly flushing, thereby destroying the evidence and proving his guilt."
Judge: "Well, if you say it, it must be true!"