At the opening, Beckett is making a cup of coffee. She is shown frothing milk than pouring it into a cup. She tastes the coffee, it appears to be bad, and she pours black coffee down the drain.
When Esposito is looking for the bug Castle planted on him, he finds it under the collar of his jacket. He was not wearing it when Castle hugged him, he had his shirt and a bulletproof vest.