-Pharaoh Sends the People of Israel out of Egypt

"Pharaoh Sends the People of Israel out of Egypt"

The opening verse of parashat B'shalach is rather challenging. The Hebrew word "Vy'he" is seen as an indication of sadness. Why sadness at such a triumphal moment? Also, the verse asserts that Pharaoh, not G-d, sent the Children of Israel out of Egypt. Can this be true?