I Smell A Bully

Lucas is barely two years old and is still trying to grasp the concept of sharing. He's got a long way to go, but for his age, he does really well.

Unless, he's being pushed too far and then, just like you or I, he loses it.

Yesterday, his Mommy lost it.

We were at Barnes & Noble and Lucas was vying for a place at the train table and a train to play with and every time he got his hands on one, another boy, an older boy would snatch it from him. 

I bit my tongue the first three times as I nonchalantly looked around for the boy's mother and helped Lucas find another train and told him he would get a turn with the one he really wanted soon.

The older boy kept Lucas and two other younger children from using an entire side of the table and at one point (and this was utterly shocking to me) pushed my son out of his way. 

No "excuse me", no "I'm sorry". Just a push.

The look in Lucas' eyes was one of bewilderment and asked what did I do wrong?. 

Grabby? Possessive? Rude? Where was this kid's manners? Better question, where was this kid's parents?

I smell a bully.

At one point, little three-year-old, Emma walked around the older boy to get to a section of the train table he wasn't hogging and he exclaimed that she "hit" him. 

She didn't touch him. Her mom and I were right there the entire time. 

Trying to set a good example, Emma's mom had her apologize to the boy and also explained that her daughter was only three and didn't mean to touch him. With that she asked how old he was.

Six.

Six? Six years old and acting like this? 

Shortly thereafter, the boy went for another train from Lucas and that was it. My poor son had had it and so had I!

I got in the six year old's face and said, "You are not being nice. That is the fourth time you have taken a train from my son. Where is your mother?"

We didn't stick around long enough to meet the mother, as Lucas, having been pushed to his limit had a complete melt down. I scooped him up, calmed him down and we went to another section of the store.

I really didn't want to be that mom, the one that flees, avoids confrontation, but let's face it sometimes it's just easier when you know you're never going to run into that six year old or his mother again.  

I know I can't protect my son from every bully or uncomfortable situation and I'm not proud of the way this scenario played out. 

On the other hand, it's not my job to discipline someone else's child when their parent is no where to be seen, is it? What did I do wrong? How do you handle situations like this?