For anyone believing any word that is coming out of "War Machine's" mouth, including that he was there to propose or that she cheated, I hope you'll read below as I deal with someone like him on a daily basis.
My sister is former military, now VP at a very well known nation-wide company. She is beautiful, smart, extremely rich, successful, the total package. She is living with one of the Presidents of the same company (they met at their current positions) and they are now engaged. My sister is an abused woman and the situations she has been in are very similar to Christy Mack. I have tried so hard to get her to leave this man, but she thinks they are soul mates, believes that she is the problem (through his mental abuse) and forgives any abuse inflicted upon her.
Her fiancee is a professional victim after any situation takes place. I've confronted him many times and all he does is make excuses. He says she pushes his buttons or it's her fault he feels jealous. He goes from beating the living hell out of her to treating her like a princess. Despite being very attractive and desired, she has low self esteem. She thinks, at the age of 36 with kids, that no good man will want her (her fiancee is like 49 - a body builder with severe roid rage) and nobody can convince her otherwise.
One time he beat her and nearly choked her to death after he had gone through her phone and found out my parents went to dinner with her and one of her male employees while in New York (they were also broken up at the time). No matter what anyone said, he was convinced she had cheated on him. She doesn't go to the hospital after these episodes (to protect him), even though I beg her to and works from home if she has bruises.
Every day I am afraid that one day he will go even further and actually kill her. He has beaten her severely in front of her kids and his. Recently, he called me after one of his rampages and I told him if I ever have evidence of his actions I will report him to his place of employment and the media (his job is high up enough that it would matter), but I doubt I will ever have the chance. My sister has sent my parents gruesome photos but they don't want to upset her so they won't give them to me. He tries to buy our family off because he has many connections and more money than he knows what to do with but I refuse to accept anything from him. I have told him many times that if he goes to therapy and changes his ways, our family will learn to love and accept him because my sister does. He says he wants that but has yet to actually get help.
Anyway, to stop derailing the thread and get back to the topic at hand, you can't believe anything War Machine says. In his mind, he is always right and she is always the "cause of" their issues or the "problem". I wouldn't doubt that he broke up with her and she felt drawn to him so she still went places with him and may have been working on getting back together. It has happened many times with my sister and every time they break up, I hope that he will just disappear. Having a man over at her house, no matter what they were doing or what relationship they had, would immediately be taken as cheating or being disrespectful even if they were broken up. With regard to the ring, I doubt he had one, but if he did... it just shows how mentally off he is. He uses things like this to "fix her" and show others that he is the good guy.
I'm sad that Christy Mack was beaten so severely but I hope it will be the close call she needs to get out of the relationship with him for good. Otherwise, considering how far he went this time, I'm afraid the next time will not end very well.