I'm sick and tired of this kind of banal and destructive comment. Please read GP again. Is "This cannot work. Case closed." really what you get from it?
I think GP is trying to understand the experiment. Pointing out issues which are problems according to his current understanding is an excellent first step to learn more.
Always adding a disclaimer that we are aware that we are no experts would be as superfluous as your answer. Don't you hate it when you teach someone and it goes like this: "Okay, what don't you understand?" - "Well... everything." Pointing out "Here's what doesn't make sense." should be a relatively obvious and welcome form to ask for clarification.
And even if you do not believe that the poster wants to learn, you could answer him in a constructive manner and thus help others with similar questions. If you cannot or do not want to do that, please ignore him.