Wimbledon organizers have apologized and explained that “human error” was the reason behind the electronic line-calling system being turned off during a match on Sunday.

Though Wimbledon’s ancient courts are no stranger to drama, this year’s fourth-round match between Anastasia Pavlyuchenkova and Sonay Kartal has set off a discussion that won’t easily quiet down. Though the Russian veteran finally triumphed with a 7-6,

The simmering tensions around Wimbledon’s use of electronic line calling (ELC) instead of line judges boiled over Sunday, when the technology malfunctioned at a crucial point on Centre Court. Russia’s Anastasia Pavlyuchenkova was serving at 4-4,