This episode was pushed back 15 minutes because of the presidential address about the government shutdown for the east coast viewers.
Reed challenges a cop entering his apartment without a warrant, who says he doesn't need one if he has probable cause. The cop knocks over a vase and uses the crash as pretext. Probable cause is what's needed to obtain a warrant in the first place. Exigent circumstances is what allows for warrantless entry in response to something like a crash. The cop acted illegally either way but offered the wrong justification.