The 2019 Ashes series became a flashpoint for the "umpire's call" controversy. Across the series, numerous LBW decisions were retained because the ball tracking showed the ball clipping the stumps with less than 50% of the ball hitting — the threshold for overturning.
In the first Test at Edgbaston, Australia were particularly frustrated. Tim Paine was vocal in his criticism, saying it was "ridiculous" that a ball shown hitting the stumps couldn't be given out simply because the on-field umpire had said not out.
The core of the debate: if technology shows the ball is hitting the stumps, why should the original decision matter? The ICC's position was that ball tracking has a margin of error, and "umpire's call" accounts for this uncertainty. Critics argued that the same margin of error should apply when the on-field decision is out — but it does, making the system asymmetric.
The controversy has persisted ever since, with players, commentators, and fans regularly expressing frustration. Several cricket boards have lobbied for the removal of the umpire's call element, but the ICC has so far retained it, arguing it preserves the role of the on-field umpire.