In your fumble scenario I would actually rather see the bad call of blowing the play dead. At least that protects the players from potential injury, and whoever recovered the ball would still get the ball.

Again, at least one of them saw it was incomplete in real time, because they made the right call (incomplete pass) without going to video review. All I'm asking is that they actually blow the whistle. Officials can be wrong and should learn from their mistakes as well.

After not blowing the whistle they should have ruled on the field as an interception, called the penalty and then went to video review. Video review would've overturned the interception ruling. The penalty would have probably still been accessed but it would be easier to swallow as a mistake by the player. As it is the refs mistake allowed for the players mistake.

As it stands they could have and should have thrown an offsetting flag for the tackle on the ball carrier. It was also a personal foul for a late hit because the ball was dead. Where as if they called the low block as a live ball penalty then the tackle on the ball carrier is legal because it was a live ball.