When Piper and Prue vanquished Shax in the street, they looked around and talked for a minute before walking away. Then the reporter is shown telling her cameraman 'back to me, back to me," before finishing her segment. When the reporter shows the people in the newsroom the tape, right after Piper blows him up, the reporter is saying 'back to me," without there having been time for Piper and Prue to have their conversation.
When Phoebe hits Cole with the potion, smoke erupts from his back. As he staggers towards her the device used to create the smoke is seen on his back several times.
The first time Cole speaks to him, The Source refers to the demon Tempus as 'Tempest'.