Why did Debra leave Dexter on the yacht at the end? Debra could've set the bomb herself and helped him off the yacht. She must've known Dexter was shot and out of it, so how did she expect him to swim to the getaway boat? This makes me think that she made the conscious choice to leave Dexter behind, thus fully destroying the evidence, and that the boat horn was a final goodbye rather than a beckoning call...thoughts?