Ocean, happy to her that you don't take offense. I'm always interested in hearing what other have to say, and while I might not always agree, I do respect your thoughts and can understand why you have the opinions you do. (And kudos to you on your advice to your son!! So glad he listened.)
I hear a lot of people talking about how Maria was a pathological liar, bipolar etc. but again I haven't seen anything other than antecdotal evidence of this. I think she was a young, immature girl who tried to manipulate situations to get her way. Sadly, this isn't unusual. Most female Marines fall into one of two (very general) categories, those who use their gender as a crutch or an excuse, and those who choose not to make it an issue. The females in the former category do not last long. The lies Maria was purported to have told appear to all have been a means to an end, attention, sympathy, money etc. That makes her dishonest, not mentally ill. Pathological liars tell lies even when the truth is plainly obvious, and even when the lies serve no purpose or have no benefit to them.
I wholeheartedly agree that she used the rape allegations to try and manipulate the situation, perhaps to punish him, perhaps to try and get his attention, maybe both. I also think Cesar cared about her, and didn't want to hurt her. I do not believe he ever intended on ruining his career, leaving the Corps, or his wife to be with her. Every thing points to a guy who loved being a Marine. I'm sure you understand that for most Marines, it's not just a job, it's an identity. Being a Marine is first and foremost who they are. As I said, I think he just wanted the threat to his identity to go away.
I also see what you're saying regarding months of frustration and lies building up and leading to an ugly scene, and a "crime of passion".
Sadly, there is no legal definition for a crime passion. It's a defense that basically claims that he didn't know that picking up a crowbar and striking her in the head with it could lead to her death. Yes, in the heat of the moment we can all do things without thinking, but where was the crowbar? Was it in his hand when they started fighting? Or did he have to look around and pick it up? There's been nothing to suggest that he had any reason to defend himself from Maria, or that, other than wielding it as a weapon, he had any reason to be holding a crowbar. So if he picked it up, it's reasonable to assume he intended to use it as a weapon. When he swung it, he aimed at her head. Again, a reasonable person could assume that, given his training as a Marine, he knew that such a blow could kill her. So, if he made the decision to pick up an object, wield it as a weapon and deliver a blow that he knew had a reasonable chance of causing her death, then by the legal definition, the murder was premeditated. It's a sad, sad situation, as it seems that if just one or two things had been done differently it could have been prevented. But no matter how poor Maria's choices were, she (nor her baby) deserved to die. IMHO he made a choice, under stress yes, but still made a choice that ended her life.
Again, just my opinion here, and I'm certainly the first to admit that I'm wrong more than I'm right.

I don't envy those jurors, that's for sure.