Togo - ////If an employer agrees to a concession, then the responsibility to ensure that the concession is implemented lies with the employer, who on this occasion, failed in that responsibility. //
Tell us how Tesco "failed". //
Certainly.
Having apparently agreed with this employee that she would not be required to sell or handle alcohol, they then put her in a position where both these aspects of her duties came into play. Ergo, they failed to comply with their side of the concession agreement.
// Why did the girl not just discreetly ask for a colleagues help, instead of making an issue of it with a customer in public? Was she making some sort of point for a white, fair haired heathen on the spur of the moment, because she knew that she could count on the backing of her employer and indeed people such as yourself? //
I have no idea why the employee did not deal with the situation differently, no-one does except for her. I would suggest that maybe she had been told to contact supervisor / manager if this issue arose, but as I say, that is speculation, because none of us were there, or have heard her thoughts on the matter.
As to whether the lady was making a 'point' - again, I have no idea, for reasons advised.
As far as the 'backing of people such as myself' - I back the lady insofar as I believe her employers fail to support her correctly as they are obligated to do, but in terms of whether or not it is right for her to be able to avoid handling alcohol, that is a separate issue.
The OP asks why no action was taken against the young lady, and I believe I have answered that, several times.