Revelation after-credits question

Finished the game and the after credits left me with some questions. I understood that Raymond and Jessica were double agents working together but where does it reveal they're working for Tricell. I haven't played re5 yet and I only learned of the name while looking up revelations

Also why are Jill and Chris just swimming in virus infected waters like they're immune? It mutated fish and other creatures but somehow Jill was fine?