That must have been a distressing experience though Lou. It happened to my son when he was about 11. he paid for a computer game in Our Price (I think) and the assistant did not remove the tag so he was jumped on outside the store and was terribly upset.
I was very mad with them and told them they had no right to jump on him unless they had reasonable grounds to suspect he had stolen something (ie they had witnessed him attempting to steal). otherwise, their approach should have been low-key.
I hope your 'goodwill' gift is worthwhile Smurfy. If you're lucky, it will be a nice hamper with wine, chocolates and a nice oven-ready meal.