Who said they were coming in to search? Not saying that wasn;t what they were doing, and maybe they told the proprietor they were there to disperse the patrons, and were sent away for that reason. But if they walk in to have a donut, what’s to stop them?
It is a key point from the legal viewpoint.
Police are allowed to enter a premis under the following situations:
1) they have a warrant
2) they have probable cause (knowing of or observing a violation of law)
3) they have exigent circumstances (someone in danger)
4) they have the owners permission
Given the fact that the cops attempted entry and were rebuffed, that means the cop knew that they did not have any of the above 4 conditions.