Murn had been a Butterfly all along, then it seems strange that he would have allowed the Butterflies inhabiting the Goff family to be killed. If Murn was a Butterfly and is secretly the mole that the team was concerned about, it would have been in his best interests to sabotage the team and save senator Royland Goff and his family. EDIT - This is not a plot hole, in the next episodes, it is explained why Murn is working with the team against the other butterflies.
When Harcourt picks Chase up from prison, as he exits the building there's white tape on the latch assembly of the door to ensure it doesn't lock on closing, something which would never be allowed on a prison door but is often used by film crews to ensure the door doesn't lock when the door closes after actors pass through.