The speaker was talking about a group of people getting what they deserved based on their actions. It is a conflation of “chickens coming home to roost” (facing the consequences of your actions) and the song “When the swallows come back to Capistrano”. This one reminds me of one of my favorite malaphors that I previously posted and which appears in my book, “He Smokes Like a Fish and other Malaphors”: https://www.amazon.com/dp/0692652205
Alabama State Representative John Rogers, in response to questions about his protests outside a hospital that is about to be closed, said “We’ll be here until the cows come home from Capistrano”. Here’s the link: http://blog.al.com/archiblog/2012/11/why_not_give_rep_john_rogers_w.html
Those swallows (or cows or chickens) from Capistrano sure get around. A big thanks to John Kooser for hearing this one.