I found this video on Youtube, and in it the narrator discusses his theory for what David did to Saw in Alien: Covenant. Pretty gruesome material depicted, as you can tell from the cover image. Check it out below.
For more information, go here.
My take: I don’t buy some of this guy’s theories, but the artwork is impressive as hell. And I do think David was experimenting pretty hard on Shaw in an attempt to make her into something else, which failed. What a monster.