Heyward was ejected from a game in the Arizona Fall League - which uses the automated ball-strike system - for arguing a third-strike call.
The 24-year-old outfielder struck out looking on a curveball that ended around his ankles. However, the pitch crossed the plate through the lower, inside corner of the strike zone, based on the ABS.
The ABS uses technology that determines if a pitch crosses the strike zone, which changes based on a player's height during the at-bat. The software informs the home plate umpire through an earpiece if it's a ball or strike.
A pitching coach in the Atlantic League was tossed in mid-July when he expressed his displeasure with the automated strike zone just one inning into its official implementation. Unsurprisingly, he was the first person to be ejected under such circumstances.