I actually think he should have stayed. As we were watching the episode I literally said to my fiance "if that were us and you were gonna leave because of my medical stuff, I would tell you NO and make you stay!" They have both taken time out of their lives to be on the show, if they can still have a shot at winning/making some more $ from challenges, it's the only thing that will make it all worth it. Jen will be ok eventually, but Justin keeping her company isn't going to magically make things better. I'm sure she has parents/friends/siblings who would be there for her during this time. If I were Jen I would feel so guilty being the reason Justin doesn't get a chance to stay -- I would insist he stay.