Until he comes up to you and asks you to hand over your can of tea. At that point he needs to indentify himself, if he doesn’t you have every right to tell him to take a hike. The officer did not i.d. himself. If someone walks up to you and wants your drink will you just turn it over?
That was my point. But UC cops tend to forget that just because they know they are a cop doesn’t mean WE know it.