Film is also subject to manipulation in the development stage, even if you avoid compositing e.g. dodging and burning. Photographic honesty is an open and active philosophic debate that has been going on since its inception. It's not like you can really draw a line in the sand and blanketly say admissible or not. Although I'm sure established guidelines would help. Ultimately, it's an argument about the validity of evidence that needs to be made on a case by case basis. The manipulations involved need to be fully identified and accounted for in those discussions.