You have to be kidding to suggest that talking about the application of an evidentiary principles, and the standard for admitting evidence in criminal proceedings is conspiracy theory. You don't agree with the facts being asserted - fine (although I note that in some cases you don't so much dispute them, as say you can't confirm them). However, the discussion is by it's very nature speculative, because no one can know if such a reprised investigation will ever take place, and what the state of the evidence would be by that point.
Lastly, if you really think there's some misapplication of the concept of chain of custody (both physical custody and access) to this discussion, by all means, articulate it. But, simple stating "you don't understand" is neither an argument nor a clarification of your view.
Let's see if you feel the same way about proper FBI investigative protocol if Mueller ever does lay any indictments against Trump and/or his organization, then demands the surrender of computer servers, and Trump says instead - "Here's a report my favourite IT contractor prepared instead. I promise it's totally reliable! Bigly!".