This is the first umpire-initiated ejection of a fan during play since Tim Welke's ejection of a Bryce Harper heckler on September 16, 2014. Prior to this, Davidson ejected a fan in 2010 for allegedly aiming a homophobic slur at Cardinals catcher Yadier Molina.
After the game, Davidson provided this statement: "This guy starts yelling, 'You suck!' You could tell he was [drunk]. And so, all right, 'suck' is not bad. Then he kept it up for two hitters completely. Then the third hitter after the first pitch, he says, 'I own property on 69th street. You could come over and suck!' That's when I turned around and said, 'You know what, get rid of this guy.'...People cheered me, which is unusual in this town for me."
The question of umpire authority to have the fan removed is answered by OBR Rule 8.01(b): "Each umpire is the representative of the league and of professional baseball, and is authorized and required to enforce all of these rules. Each umpire has authority to order a player, coach, manager or club officer or employee to do or refrain from doing anything which affects the administering of these rules, and to enforce the prescribed penalties." Thus, when Davidson ordered security (e.g., game management/the club employee) to remove the fan, Davidson himself was employing Rule 8.01(b). The key is that Davidson went through a team employee to have the fan removed, rather than directly ejecting the culprit himself ("I turned around and had the guy get rid of him" -Davidson).
Wrap: San Francisco Giants vs. Philadelphia Phillies, 8/2/16 | Video available via "Read more"
Alternate Link: Davidson halts play to request security remove a fan at Citizens Bank Park (PHI)