The Murder of Francis Macomber-Was It Intentional?

At the end of "The Short Happy Life of Francis Macomber" by Ernest Hemingway, Francis Macomber get a bullet in the back of his head-a bullet shot by his wife, Margaret (Margot). The question is: was the murder intentional?
I honestly think that the murder was intentional, not because of the forensics or anything like that, but to the many motives that the reader is clued into, and to the reaction of Wilson, the main witness.

Margot's two main motives seem to be the pursuit of Macomber's fortunes, and the fear that she will be kicked to the curb by her husband, and his newfound confidence. Their relationship is an interesting one. We start by finding out that "Margot was too beautiful for Macomber to divorce her and Macomber had too much money for Macomber to ever leave her." This shows an interdependence. Their relationship is also definitely unstable, as we are clued in that she left Macomber in the night. It is also worth noting that this shows the relationship is based on anything but love.  Macomber can't get a better lady because he isn't very good with girls, and is a "coward" (as he was called by his wife), and Margot can't find a man with any more money. The reader is told that she is a former model, key word former. This can be gathered from the quote, "five years before, commanded five thousand dollars as the price of endorsing photographs, a beauty product". She was a model, a very beautiful one, and she is still pretty, yet she has lost that sparkle that she had once had. A younger, prettier woman has probably surpassed her. The importance of this however, is it creates this tug of war of power. The minute she finds out that Francis had been cowardly and ran away from the lion, she got excited and said she "wouldn't miss something like today for anything". This shows her excitement, that her husband is also losing some of his past sparkle being a "four-letter man" (a successful sportsman in school).
Everything changes however, after Macomber kills the buffalo, and becomes a hero. During the hunt, he has a newfound confidence. This is apparent when it says, "For the first time in his life he really felt wholly without fear. Instead of fear he had a feeling of definite elation". This is noticed both by Margot who "saw the change in Francis Macomber: and by Wilson, who congratulates Wilson. One can also see Margaret's fear when she says, " 'You've gotten awfully brave, awfully suddenly,' his wife said contemptuously , but her contempt was not secure. She was very afraid of something." This something could definitely refer to this fear of losing power in the relationship, and not having the upper hand. She is scared that if her husband is confident, he may leave her, and with that she would lose the ability to get a good man, and the money.
This described the motives of money and fear of her husband having the upper hand and the control. Of course, even with all these motives, she may have killed him on accident, but she did shoot him straight in the back of the head, "base of the skull" so it couldn't have been aimed at the bull. She probably didn't plan it thoroughly considering she hasn't ever shot a gun or anything, but she seized her opportunity.
The other aspect that could point to this murder actually being intentional was the reaction of Wilson, the main witness.
Wilson, doesn't make any outwards exclamations or shrieks. He also tells her that "That was a pretty thing to do," he tells her in a toneless voice, "He would have left you too". By pretty, he does not mean beautiful, but that killing him was a big thing to do. The second phrase further supports the described motive of the fear of him leaving her. He also asks why she didn't "poison him" since "that's what they do in England". Since poison is an extremely direct and intentional murder, Hemingway may be showing that this was too. Finally he agrees to help her, probably for the money, since he understands that was also part of her motive. he continues very monotone, indicating he is neither upset nor excited, a weird reaction when someone has just died.
Overall, the way I see it, the murder of Francis Macomber by Margot was intentional because of the potential motives, and Wilson's reactions.

MicroFiction Hemingway Style

1. Girl in wheelchair leaves Aldo dejected.
2. Three shots, a final gasp, silence.
3. Funeral: 'Till death do us part?
4.  Wanted a mother; got a babysitter. 
5. Anxiety ridden children run through halls.
6. "Parent Night" makes her tear up.