I think your suggestion of leaving it open-ended is a good one, FWIW, but I honestly thought the whole book was trash, so it’s hard for me to say that this one change would have made a significant difference in quality. The author zooms through the whole trial and seems to care so little about it, that the whole “guilty, not guilty” question is rather moot to me. It isn’t as if there’s a ton of focus on evidence and debunking evidence and debating the method of debunking, the lawyers going back and forth. There’s just an occasional testimony, some light cross-examination, and then Kya zones out again, so the narrative stops tracking the courtroom events. The question of whether she killed Chase is apparently unimportant to the author, so its resolution was unimportant to me as a reader.