Perhaps the staff denying them service was black and they are white? Do we know details?
The other criteria is the person denying service has to say WHY they are denying the service, and it must be because of the specific conditions below.
“We dont’ serve crackers here”
Or, alternatively, a long term pattern of denying without saying why.
For instance: If Whites were never seated there.
There is no case here.
None.