The Hawk-Eye system predicts the trajectory and motion of a cricket ball right from the point of its release by the bowler to a certain point behind the wickets after which the ball is considered dead.
Some argue that Hawk-Eye predicts the motion of the ball purely based on the pre-bounce behavior and so has an inherent flaw owing to the fact that the cricket ball has a “seam” around its equator and there might be chances of the ball behaving differently post-bounce.
According to them, the trajectory from the point of bounce till the wickets needs to be built from the post-bounce actions of the ball.
It is true that even if the Hawk-eye considers the post-bounce behavior and makes a projection of the motion with the aid of cutting-edge prediction strategies and statistical models, there is no possibility of arriving at 100% accurate decisions every time.
We need to understand that leg-before-wicket decisions were prone to controversies even before the advent of Hawk-Eye. A certain percentage of error is inevitable when it comes to such critical decisions since it is human to err.
There is no wonder a human-invented artificially-intelligent prediction system makes a specific amount of error while aiding the decision-making process and thus it is absurd to suspect the integrity of the Hawk-Eye system.
Somehow all these remind me of Robert Orben's saying:
"To err is human—and to blame it on the computer is even more so."