The ending and my take on it ***Spoilers*****
[spoiler]
So the film built up a good case as to why she should hate this vile man.
I mean she couldn't wait for the resistance fighters to come in and blow off his head while they were making love.
Then suddenly, he gave her bling and that shiny diamond completely changes her mind and suddenly she is in love? What the Hell!!!!!!
Few things come to mind:
1) The ending serves as an example of how superficial and materialistic women are by nature; willing to sell out their virtuous beliefs and ideology even for a abusive and dubious relationship. She sold out the lives of her friends for goodness sake. We see this in modern society all the time; women marrying for money, only dating men with a fat wallet. I'm sorry but her facial expression when she saw that diamond was not convincing of her a woman who fell in love with the man or the relationship itself but a woman who fell in love with wealth and status.
2) The writer was trying to make the point that she fell in love with this vile person. But the film did a poor job of showing the progression from hate to love.
All I see was a woman enamored by the shiny diamond.
3) As the title implies, the main character had for a brief lapse in judgment and allowed her lust/love to get the best of her. When it was said and done, she realized it was too late and her action was indeed irrational.