When toddlers attack

We decided to go out to purchase a magazine last night at our local big bookstore. We had an hour before bedtime and no plans so it seemed like perfect timing. Unfortunately, the magazine we were looking for (the one with the stucco repair dad) was not there, so Hoagie and I headed off to the children's section. Oh the delights of the children's section! Hoagie could hardly contain himself. It was pretty empty and he was enthralled with the large train set that was set up in the corner. Another couple headed over with their two boys (one about 4 and the other around 2, plus one on the way) and the younger of the two had a major meltdown. Like monumental shrieking that would have sent me right back out the door to put my kid to bed. Alas, these parents decided the kid should play at the train table with his brother and Logan. As you are probably aware, a one year old has almost no sense of things belonging to someone else. Very, very little. So he tried to take the older brother's trains and I herded him away several times. The parents of the other kids were nice enough and we traded quips on what it will be like to add their expected child into the mix. Then Logan made a most dire mistake. He grabbed the younger boy's train. The shrieking! The yelling! In no time at all the boy had Logan around the neck and was strangling him. Well, not seriously, but enough to scare the pants off of our boy and send him into hysterics. I intervened along with the other parents and we left the train table. The strangler's parents apologized profusely and no one was worse for the wear. Personally, I would have left the store then if my kid had done that to someone else, but (you may detect a theme here) they decided to stay. We left as it was Hoagie's bedtime and many more apologies were offered. So that was our first experience with a physical altercation between our kid and another. Don assures me that I didn't freak out, even though I felt like my eyeballs were going to pop out of my head when I saw that little boy's hands around my son's neck. I think I said something like "Oh no, we don't do that!" so how bad could I have sounded? I always second guess myself when I am talking to or correcting other people's children. I wonder how T deals with it at daycare? I have much to learn today when I pick up the kid.