Get your hands off my kid!!

So I was at a park a couple days ago with my family to let my kids run around and play for a while. My oldest son who is three years old was playing at the playground where there were a lot of other kids playing as well. My son brought with him a little toy car that he was carrying around with him for most of that day. Whenever I am in a crowded place with my kids I am so paranoid that i almost cant relax because I am constantly watching them and making sure they are okay and especially no creeps do anything to them. As Charlie (my son) was playing he found a friend who was about two years older than him and they seemed to be getting along just fine until he pushed Charlie down and took his little toy car! I was so mad at this little boy but I want my kids to work out problems like this on their own as much as they can so they can learn to not depend on mom and dad for every little struggle they encounter. As Charlie got himself up he looked at this bully and said "give me back my car" the boy said "no" so Charlie hit him! I was on my way to them when just before I got there this boys mother grabbed my son by the arm and while pointing in his face said "NO! NO! NO! We don't hit!"
Poor Charlie was terrified! I said to this woman in a very protective manner "Get your hands off my kid" I explained to her that she had no right to touch my child or discipline him! I was so angry! I watched the whole thing and not that my son was right for hitting the kid but she just had no idea that her son stole Charlie's car and pushed him first. She told me that I need to teach my kid some respect and not to hit! I told her that she should practice what she preaches, I saw that this conversation was going absolutely no where so after making Charlie apologize to the bully I removed him from the situation and we left the park. I still cannot believe how bold that woman was to discipline my boy in the manner that she did!