"I wouldn't worry about that"

I've posted this in the category "English language" rather than in "humor," because the cartoon made me rethink the use of the title phrase.

The full phrase is, of course, "I wouldn't worry about that IF I WERE YOU."  But it is often - perhaps typically - shortened to "I wouldn't worry about that."  Which, taken literally, means something quite different, and which can properly be used in the sense that Dilbert's boss uses it.  I'll have to try this...