Ten Little Indian hpw does captin Philip lombard die?

After he and Vera Claythorne discover the body of Dr.Armstrong they both suspect each other to be the murderer. Vera tells him to move the body out of the reach of the sea and there she picks his pocket for the revolver. When he realizes she picked his pocket he jumps at her to try and get it back and she shoots him through the heart in midair.

(According to the book)