Obviously I'm missing the point of your OP. Could you rephrase your actual question? You ask for a rationale behind something, but with all this new information about how you did and didn't intend it, I find it hard to believe that you want to know why you get a warning. After all, you're perfectly aware that you've broken things on purpose, just to get that warning. Please help me understand your question (i.e. which rationale), and how your code snippet relates to that.

Other replies in this thread have been very similar to what I have replied, so I can't be the only one who has not managed to parse your OP right.