Retail Fraud / Shoplifting: Shoplifting With a Friend

My question involves criminal law for the state of: California

So the other day, my friend and I decided to go shoplifting at Loehmann's. I saw a wallet there and I wanted it so I went into the fitting room ripped the box off and put the wallet in my pocket. The wallet was valued at around $19.99, original price was $79.99. My friend however took 2 sweaters and put it in his bag, valued around $200 together. Just as we stepped out the door, the Loss Prevention manager grabbed us by the arm and said "give me the wallet" along with two Loss Prevention security guards waiting for us outside. After I gave the wallet to the manager, she looked to my friend and asked "what did you take?!" Out of bewilderment, my friend gave up the 2 sweaters that he had hid in his bag. So we went into a room in the back of the store and they asked us for all our information. They called my mom, because I'm 16 and considered a minor, and told her to come to the store immediately. As for my friend, who is 18, he had to deal with this himself. The department later called the police and the police handcuffed us and took us to the police station where I was required to give all my information, scan my fingers, and take a picture. When the police asked us questions, I told him that we were carrying a bag for "easier access to steal" and that we decided to steal few hours before the incident. He told us that because we had planned this it was considered a felony. What I was wondering was.. while waiting in the room for the Loss Prevention staff to review the recording of the security camera, one of the security guards who claims to have majored Criminal and Justice told me that we could have gotten away had we knew our rights. Does anyone know what right he is talking about? Did the manager do anything wrong when she grabbed us by our arms? Should we have kept on walking because technically the staffs do not have the right to search me. Please help me!