I am with others that I think their marriage was going through changes that might have been tough. In the long interview on his driveway, he mentions specifically that Missy had changed from a stay-at-home mom to someone who became passionate about fitness. Suddenly having your wife have interests in herself and wanting to make a difference in the world (beyond being focused only on the family) can be a difficult shift in the marriage.
ALL marriage go through changes, and I think the time when the children are older and the mom starts to "reawaken" to her own self can be hard on some husbands. It doesn't necessarily mean divorce or estrangement, but it can mean growth pains as the marriage dynamics shift. Also, middle-aged men might feel in a rut in their career or a bit bored, while his wife is growing into a new stage of excitement and possibilities. It can create the awkward feeling of wanting your spouse to succeed, but also wanting things to stay the same. Missy was receiving kudos and admiration from others, which doesn't mean the husband was jealous....it was simply a new phase of their lives and might have required some adjustments.
Change isn't easy.
Finally, I have to say Missy has inspired ME. I am actively increasing my own physical fitness since this case. After a death in the family two years ago, I became more sedentary than my usual self.....and learning Missy's story has DEFINITELY given me encouragement to get back into fitness. I've walked several miles in the past few days, and it feels great. I've never been so personally touched by a case. Thank you, Missy.
JMO