What a weird and strange ending, who shot the son at the end of the movie ?

The maid should have taken the envelope and not say anything to the Father and left the house. Later, if she wanted to ,she could have reported what she knew to the Police . The money she could have claimed was her severance pay, no one could have proved how much was in the envelope . If she was afraid because she was an illegal immigrant, I am pretty sure that she would have received immunity and be allowed to stay in the country for helping to solve a crime .