Mr. A walks into the store of a very well known cheapo supermarket. The security alarm goes off, triggered by something unknown, possibly in Mr. A's rucksack. The man behind the kiosk looks up at him but expresses no interest. Nobody investigates what triggers the alarm so Mr. A continues into the shop. 5 minutes later he exits. The alarms go off again. The man behind the kiosk again looks up with casual indifference. So Mr. A proceeds into the car park. Two store workers follow him. They ask Mr. A to come back into the store. Mr. A explains what has happened. Nevertheless he is to come back into the store. Mr. A refuses. One of the store workers grab his arm. They insist he turn out his rucksack. Mr. A refuses. The store workers say they will not let him go unless he returns to the store or turns out his things. Mr. A says, on that basis, he will only allow the police to search him.
The police are called, Mr.A is searched, nothing has been stolen. A coil of wire purchased from another electrical shop has triggered the alarm.
If Mr. A were to pursue a civil claim, do the store workers have a valid defence under section 24a of PACE of reasonable suspicion? Would this defence scupper any chance the claimant has of bringing a civil action in respect of false imprisonment, assault, battery?