In 2013 Corbyn said ‘Zionists have no sense of English irony despite having lived here all their lives’. He claims that he was using Zionists in the strict political sense rather than as a euphemism for Jews, but people aren’t born with a political ideology like Zionism. Even Corbyn wasn’t born a socialist. At best this was lazy thinking (and just a stupid and nasty thing to say) at worst it was anti Semitic. I’m not sure which.
I met him once, or was in the same place as him, the Queens Hotel in Crouch End in 1983, before he was elected to Parliament, when he was part of the Hornsey Labour Party. Just a typical dim agitprop ignorant Trotskyist who never bothered to understand the theory in those days, and I don’t think much has changed (I have no evidence, it’s just an opinion). He was distributing a paper called London Labour Briefing which he wrote for, specifically on opposing the expulsion of the Trotskyist entryist Militant faction from Labour, and which later supported the IRA Brighton bombing of the Tory Conference. He might be nice to your face, he is a politician after all.