If a jury cannot follow (what is assumed to be) basic rules
That's why you got down voted: you assumed something, without knowing, and you were completely wrong. Read a jury's instructions just once, and then let us know how basic it sounds then.
This is why I started with the question, "How difficult is it to understand the rules[?]".
I haven't seen the rules posted anywhere, or any real discussion on the rules or how hard they are to follow. Have you?
Also, I'm not sure what is wrong with the assumption that jury rules should be "basic", as in, understandable to a jury member. Do you assume that jury instruction should be complex, complicated, and not understandable to a jury member?
The way you phrased the question makes it sound rhetorical. "How difficult is it to understand _______?" is almost always a rhetorical question; if you genuinely want to inquire about the difficulty, you kinda have to bend over backwards to make that clear to readers.
I guess I just don't see it ("How difficult is it to understand _____?" being a rhetorical question). It sounds like a pretty straightforward and legitimate question to me. Of course, your perceptions may differ.
That's why you got down voted: you assumed something, without knowing, and you were completely wrong. Read a jury's instructions just once, and then let us know how basic it sounds then.