

Prof Kerry Brown, the director of the Lau China Institute at King’s College London, said an official of Cai’s level having a line of contact with a foreigner, even in cases of intelligence gathering, was “very, very, very unlikely”.
Members of the politburo “really aren’t accessible”, Brown said. “Particularly under Xi Jinping, [they] don’t really have any liberty to do anything too entrepreneurial.” skip past newsletter promotion
Brown said the case “raises questions about how British security services assess information in China”.
I find this story to be the most likely. Even I don’t have time to talk to two random foreigners about gossip
Did it really though? Ruffle is a reimplantation of Flash in Rust, and is available as a browser extension. Anything short of malicious swf files will play. So it seems that any “security issues” were clearly mitigatable.