Would the merchant's defense relieve store managers from liability under the cause of action of false imprisonment?

At 2:20 p.m. today, I observed a customer, Candice Cook, who was standing next to calligraphy sets in the store, make a sudden move to her pocket. She then proceeded at an accelerated pace toward the exit. I noticed that her side pocket was stuffed. I then proceeded directly to where the customer had been standing and noticed that a calligraphy pen set was missing. It so happened that I noticed earlier that day that the calligraphy pen sets were fully stocked up. I assumed that the customer, who I had previously observed, had shoplifted the set. As the customer was about to leave the store by then, I began chasing after her and reached her at the store's entrance. Fearing that I might lose her in the crowd, I shouted at her to stop. I then grasped her by the arm and shoved her back to the store. Apparently, the customer lost her balance and fell on her back hitting one of the checkout counters. She seemed to be hurt a little, but then I offered to help her stand up, although she continued to limp. I then asked her if she had forgotten to pay for something. She seemed surprised and said that she does not understand what I am talking about. I then directed her to follow me to the Loss Prevention room. Alice Fernandez, one of the checkout employees, helped her walk toward the Loss Prevention room as the customer complained she was having difficulties walking and was experiencing terrible back pain. I closely walked behind the two of them. Per store's protocol, I then advised the customer that she would have to wait until the store's manager would come back from a meeting for the investigation to begin. The store's manager, Jackie Tran, was due to return from a meeting at 2:30 p.m. that day. Unfortunately, she only returned at 3:30 p.m. At that time, Mrs. Tran advised the customer why she was being held up and asked her to empty her pockets. However, no calligraphy set was found. Mrs. Tran then apologized for the inconvenience, gave her a $25 gift certificate, and wished the customer well. I really did not mean to hurt the customer, but apparently, her fall did some damage to her as she kept complaining that her back hurts.