I asked Theresa Carling, Employment Law Associate for her comment:

"This appalling example of how not to act when you believe that you may have an issue with a customer is a worthy reminder to employers that you will almost always be responsible for the actions of your staff.

Bear in mind that, as an employer, you have an obligation to treat all of your customers the same. Your staff need to be trained not to single out any customer on any prohibited ground-i.e. sex, race, sexual orientation, disability, age or pregnancy. It is always worth remembering that where they act badly, it may still fall on you to pay up where one of your employees treats a customer (or a colleague) less favourably. Whatever the reason for the action or treatment, bear in mind that if you or your staff can’t justify an action then you should expect to face the consequences as Tesco have in this case.

Equality training for all employees is always recommended to avoid issues like this arising. I expect that there will be more of these types of claims given the publicity this case has received…"