 In the original Japanese version the message Vincent puts out to citizens is  read by him. In the English dubbed version Jet reads it off the screen. In  the English dubbed version when Spike comes back to the BEBOP with Electras  vaccine and Electra herself, Spike says to Jet, "Heard from Bob?" This line  (absent from the Japanese release) makes it clearer as to how Jet knew the  ISSP was at the water treatment plant.