What legally might happen if a customer helped stop a shoplifter?

I walked out of the grocery store today and heard some ruckus behind me. I look back and a short manager was trying to apprehend a shoplifter who was running out the door with 2 large cases of beer. The manager had the guys elbows back but was straining and the shoplifter was using his leg strength to try and break away. I saw this and grabbed the guys legs and we took the guy down (no harm was done to him at all). We were worried about the guy having weapons and we wanted to get him back into a holding room to await the arrival of police, so I frisked the shoplifter and we got him up and back into the room. After 30 minutes the police still had not showed up so I decided to leave but I left the manager my phone number and name. I've not yet been contacted. Are there any legalities I should be aware of?