Again, you are assuming that the ball will never move more than what it moved at impact. An umpire can judge that, hawkeye cannot. And there are 3 or 4 people involved who work on Hawkeye and if and when they get it wrong, the human error there is gonna cause hell of a lot more damage than any umpire's error has. And I understand they do not stop the hawkeye's tracking at some random point and then use the predictive path to compare it on a match to match basis. Which means, all the experimentation and results provided can be of no use, if they had been so much as a 1mm displacement of one of their 6 tracking cameras, which is perfectly possible. And from reading up on the Hawkeye guy's PDF where he has shared his mail communications with Mickey Arthur and some screengrabs, it is even more obvious that they NEVER provide for exaggerated deviations at any point after pitching. They track the ball till impact and extrapolate from there.
If that doesn't drive home the point, consider a 90% vs 95% situation. 95% is still better than 90%?? What of the fact that only 50% of the decisions by the technology are accurate? You could just toss the coin rather than use the 95% accurate technology.
Technology doesn't make mistakes ffs. And if the accuracy was as low as 50%, then it wouldn't be getting used.
You're building a straw man argument here.
edit: and ironically, it will be through the use of technology that you declare a decision to be incorrect.
A genuine question here: What if a full toss from a spinner hits a batsman on the front-foot by the way? Assuming the ball was supposed to pitch before reaching the wicket, how is the DRS going to review the decision?
2.5m rule comes into play?