That's not what I was saying, I was responding to a statement about documents "infecting" one another which is clearly incorrect. But even if I _had_ said that

That's not what I was saying, I was responding to a statement about documents "infecting" one another which is clearly incorrect. But even if I _had_ said that, you're still not correct. In a contractual agreement, the legal document _itself_ is not what has the "power" in the agreement -- the agreement is what matters. To whit, contract law applies in cases where legal documents are not actually written down (you can even have implicit contractual obligations) and due to the requirement for "meeting of the minds" there can be cases where a contract doesn't have the power that it may claim it has. Of course, a legal document is a much more formalised agreement (and obviously they are a very useful tool to make sure that the precise agreement is laid out) but just because it's more formal doesn't implicitly mean that the document itself is somehow imbued with some mystical force to effect consequences. I'm not a lawyer, but I have discussed this topic with lawyers in the past.