What's anti-semitic about chanting "Kill the Jew"?

BDS is, of course, the acronym for the international campaign pushing "Boycott, Divestment, and Sanctions" against Israel and Israelis. Here's an item about the South African branch of BDS, posted a week ago by David Hirsh:

As an Israeli plays sax at a South African University, protesters sing: “dubula e juda” (“shoot the Jew”). Muhammed Desai, coordinator of BDS South Africa, explains how this is not antisemitic:

'Desai said many African people in South Africa when using the word “Jews” meant it in the same way they would have during the eighties. “Just like you would say kill the Boer at funeral during the eighties it wasn’t about killing white people, it was used as a way of identifying with the apartheid regime”.'

'"He said there was no evidence of Jews being harmed because of anti-Semitic impulses, – “the whole idea [of] anti-Semitism is blown out of proportion”. He said if there were anti-Semitic sentiments they would flatly challenge it even if it came from within their protest.'

WITH GALLERY & AUDIO: BDS protests Daniel Zamir concert at Wits

(Apparently, a few BDS activists in South Africa disagree with Muhammed Desai on this point—some Jews and Jew-lovers, no doubt; those people are always touchy and paranoid—but he's the national BDS coordinator.)

—Jeff Weintraub