Fumble returned for touchdown negative points
Player that fumbles and in return allows the other team to score should be an option for negative points. Some referred to it as a fumble 6. Like a Pick 6.
Thanks for your feedback.
We will get your suggestion to our product team. If you are in a Private League, the commissioner has the ability to edit team points if the league wants to enable this as a rule. They would just have to manually keep track and edit the points to account for this.