Precisely so. I agree with Belisiario.
"Here is the kicker". would be a way to get you prepared to have a laugh, or expect something that is surprising in kind. Perhaps it was unexpected at the time, but you (that is using the expression right now ) So the listenener/expectator/reader knows beforehand that something ironical and unexpected, outraging and unexpected or funny and unexpected happened...(in such a way that it turns into a "highlight". -ponto alto da história.)
Longman Exams Dictionary (for Intermediate - Advanced Learners):
Kicker - a surprising or unexpected end to an event: the kicker came when the reporter asked when the reporter asked the 22-mile runner wether he was tired. (o engraçado/inesperado/a ironia da história...etc... foi quando o repórter perguntou...)
The kicker came when we got out of the plane and discovered he had lost his teeth with his lunch.
(a parte engraçada, o principal da história, a grande surpresa, o melhor da história - que estava por vir... foi quando a gente saiu do avião e descobrimos que ele [o pai do autor] tinha perdido a dentadura [false teeth] durante o almoço.
((( Takeoff: Career Adventures in General Aviation and the FAA, by Por John R. Hull )))