It was literally and figuratively amateur hour yesterday in the LPGA, as Lexi Thompson basically had a probable victory at the ANA Inspiration tournament, one of the LPGA’s majors, taken away from her by a busybody fan.

In a move that is almost too bad to be true (and one that makes Dustin Johnson’s experience at last year’s U.S. Open seem like a walk in the park), Thompson was assessed a whopping four-stroke penalty with six holes to play in yesterday’s final round for an incorrect ball placement made the day before.

Here’s the kicker. The only reason that the LPGA found out about the incorrect ball placement is because a goody-goody fan noticed it while watching on television and decided to e-mail the LPGA about it. While most professional sports leagues would probably take weeks to get around to an e-mail sent to them by a fan, since literally nobody ever e-mails the freaking LPGA, the e-mail was noticed and followed up on fairly quickly.

After reviewing the footage, the LPGA agreed with the fan that a violation had occurred and, with the most unfair decision in the history of professional sports, waited until Thompson had a three-stroke lead with six holes to go in the final round before informing her that her lead was now completely gone because of something that she had done the day before.

Thompson was still able to compose herself and fight through it. However, she later lost in a playoff and was visibly upset. Even the tournament’s victor, So Yeun Ryu, remarked that her win didn’t feel right.

Skewing the outcome of a major tournament due to a tip from a fan is ridiculous. There are likely several minor rule infractions not picked up on by rules officials throughout play that fans might be able to see at home. But here’s the thing: most fans aren’t so full of themselves that they would think to send an e-mail to the LPGA to draw attention to a potential rules infraction.

Imagine if a basketball fan noticed while watching Game 7 of the NBA Finals that a player didn’t get a made shot off in time that the officials ruled to be good and e-mailed the official NBA e-mail account about it, thus sparking Adam Silver to decree in the fourth quarter that the score had been changed. Now, imagine if the team that had points taken away ended up losing by one point. Don’t you think that the sports world would implode with outrage and hot takes?

So if the LPGA wants to be considered one of the premier professional sports leagues, doing amateurish stuff like affecting the outcome of a major due to an e-mail from a fan is not the way to go. And as for the fan who sent the e-mail, get a hobby. Because snitching on professional athletes via e-mail is a weird way to spend a Saturday.