NOTE: Per wiki policy on Fridge pages, spoilers may be unmarked!
Fridge Logic: It's later revealed it was Storoni who arranged Ellua's accident in both timelines in order to make Calmia the countess. However, since it failed in the second timeline, it begs the question why Storoni never made another attempt then, since he had plenty of opportunities in the meantime. Calmia's - whom Storoni loves - engagement to Rudbeckia would actually serve as another motivator to get rid of Ellua, since (as she herself points out to their father in hopes of convincing him to make her the heiress) if Calmia became the countess, she would be expected to carry the family name, which would preclude her marrying into a more powerful family and taking her husband's name.
Somewhat explained: according to him, he decided against trying to kill Ellua again, seeing how much Calmia cared about her brother after he almost died.
