Playgroup punchup

Well, not really, but a kid at playgroup yesterday really pressed my buttons and I didn't handle it at all well. Asher was playing on a gym mat outside with a little tunnel thing for kids to crawl through. There was a little girl of maybe three sitting in the tunnel and when Asher crawled over she pushed his hand away. I don't really know playgroup etiquette for dealing with these situations so I was really friendly, saying something like 'hey, he's just a baby and he doesn't want to come in there with you, so it's not nice to push him' but she reached further out of the tunnel and pushed his face away. He wasn't at all hurt or even made uncomfortable by this but I was starting to get pissed off with this kids so I said, in a more serious, less friendly tone 'hey, if there is a problem talk to me, don't push him' while very gently taking her hand away from my kid. She of course stared at me and pushed Asher again so I very gently took her hand, moved a little closer to her, looked into her eyes and said in a really slow quiet threatening tone 'don't push him' and at that moment her mother appeared and hassled her about playing with the baby toys and took her away. I felt bad about it because I feel like I handled the situation really badly - I (kinda) disciplined another person's kid, I told her 'don't' rather than give her an alternative and the worst part was that I basically got into a power struggle with a toddler, and I know from bitter experience that those power struggles are pretty much unwinnable. I guess I should have just picked Asher up and taken him to play with something else, but I hadn't had my coffee and I got all mother-bear protective of my kid.

Unfortunately (heh, it gets worse) this all happened just minutes after I had been (mentally) criticising another mother for the way she was disciplining her child (who was also pushing Asher - does my kid wear a 'push me!' sign that I can't see?). She had been telling her just barely two year old to 'stop' (not being specific) and vaguely threatening him with going home. We had been half chatting and she had been bitching to me about the fact her son has started pushing other kids (yep, loud enough for him to hear) while I, sitting atop my very high horse, had been thinking of Moxie's advice and that she should try diversion or gently getting between her kid and my kid if she was upset about it rather than vague whiny threats about going home. Everybody has bad days and when they are tired and harrased and the best way of dealing with toddler stroppiness isn't always obvious so I would like to unreservedly retract my judgemental and narky thoughts.