The boyfriend of Giselle Tapia-Salazar, the mother of fourfound hanging from a Texas dock, is maintaining that he had nothing to do with her death, as investigators comb through thousands of video files, looking for clues as to what really happened to her. James Hart claims that Giselle got up to use the restroom in the middle of the night, and never returned. “There are so many questions and there’s no answers. I don’t understand why because we have cameras all over this marina,” Hart said through tears in an interview with KHOU, “there should be no doubt about this. There should be no way th…