Jesus on the other hand should be held to a different standard. His speech should reflect that he understood scientific matters as he is held to either have set the rules and been the implement of creation, or at the very least been present for the creation of the universe.
My view is it wasn't meant as a scientific statement. It was a statement about imaprtiality, as others haev been saying. It was a simple analogy to explain the prinicple that God did not discriminate between those he felt were good and those he felt were bad when it came to providing the natural provisions he set in motion at the begining of creation. He wouldn't stop sun or rain upon someone because they were unrightous. This is really clear when reading the surrounding verses. Its seems that the writer is talking about impartiality.