You answered your question yourself: "haven't taken into account all possibilites" which roughly translates to bereaving yourself of the Fine Art of Globbing. If you don't want to increase your globbing mana, just do "cmd 2>/dev/null" and suddenly, all your troubles will seem so far awaaay, doesn't look like they're here to stay, Oh, you believe in yeh-stuh-daaay. You believe in yeh-stuh-daaay.
Hmm. Now where did that come from...