It wasn't unilateral. Haringey's manager said:
"Yeovil’s manager and players were different class. Their team tried their best to calm their supporters down, and they said if you’re walking off, we’re walking off with you.”
Also, one of the players who was abused tweeted:
“Can’t believe I’m tweeting this and it’s 2019 but today I was a victim of racism in what was supposed to be a great day for @HaringeyBoroFC. Another game of football ruined by racists. Thanks to @YTFC players and staff who backed our decision to leave the pitch.”
https://www.theguardian.com/football...vil-fa-cup-tie