I'm currently writing a Dramione fic in which Draco has turned to Harry, Ron, and Hermione in order to protect his (and his family's) future and well-being, and ultimately, help the "trio" destory Lord Voldemort. In the fic, Draco has basically turned/betrayed his family, at least in his mind.
While dueling his Aunt Bellatrix, Draco is badly injured and getting ready to face death from his Death Eater aunt. However, in the fic, I have Lucius sparing Draco's life, stopping Bella's murder attempt. I have Lucius not turn his son in to the Dark Lord, even though Draco has betrayed his master/shamed the family in Voldemort's eyes, and also letting Draco return with Harry, Ron, and Hermione. Basically, he saves Draco, but leaves him on the battlefield for whomever Draco has been helping to find.
My concern is that this would not be in Lucius' character to do. I was hoping for some feedback, hope this is the right place.