Official institutions talk about evidence, but a dangerous organization like the Rejuvenation Society doesn't need it.
Fang Ze was originally "a Rejuvenation Society spy lurking within the Security Bureau." He was to pass intelligence to the Rejuvenation Society.
So, he conveyed the information he had gathered, along with Hua Jian's true identity, to the Rejuvenation Society. By the way, he also let the Rejuvenation Society know that Hua Jian was now being watched by the Security Bureau.
If they wanted to continue tracing the Shadow Organization's clues, if they wanted to know Qin 28's whereabouts, and if they wanted to keep this lead from breaking, the Rejuvenation Society had to act first!
Based on what Fang Ze knew of how much the Rejuvenation Society valued Qin 28, he felt that the Rejuvenation Society would most likely not sit idly by but would take the risk and deal with Hua Jian.
