One of my few issues with Casino Royale centers on Vesper’s secret dealings. After the traditional first watch “glow” wore off like it does for me with every Bond movie after subsequent rewatches, the Algerian boyfriend retcon felt less like a shocking twist and more like an underdeveloped explanation.
Vesper appears so emotionally vulnerable throughout the film that her betrayal lands with a bit of whiplash. A few brief scenes showing pressure from her handlers or correspondence with her ex would have made her “impossible” choice feel more believable. Instead, the revelation arrives almost entirely after the fact to the story’s detriment. And it doesn’t help that it’s delivered by M to Bond, via phone conversation. Why not have a more direct face-to-face sequence at minimum?

