There’s nothing wrong with the point you’re trying to make, but the particular example is awful. The cash is worth its face value no matter whether there’s a nationwide aversion to Dishonest Abe - you can still use them to pay taxes, etc., or the central bank will exchange them for $10 bills, etc.
My point is what if it’s not worth it’s face value? Clearly, it wouldn’t be to the market if (as in his example) the stock was priced at $1. So I was trying to think of an example (obviously not a very realistic one) where this could be the case, that’s all.