Extremely poor customer service

I had a really bad restaurant experience this weekend. I thought of just letting it go but it's been haunting me this whole week as it affected my kid. On Sunday I went to the Waterfront with my kids, my sis-in-law, her husband and their child. They suggested that we go to Primi in the Waterfront. I knew my son does not eat anything off their menu but I agreed because he was the one out of the six of us. I then thought I could just get him a small takeaway and he could still join us at the Restaurant. We got a table, sat down and ordered. The kids naturally went to check out the play area first and my son came back 5 minutes later asking if he could eat. At this point our drinks had already arrived and our food (5 meals) would follow shortly after. I took out his noodles from Simply Asia and he sat down and started eating. My 3 year old daughter now needed the bathroom, so the 2 of us leave to the bathroom which took us about 5 mins. When we returned, we returned to an empty and clean table, which was really confusing because when we left the table was full of things. I confusingly looked around thinking I could have been mistaken or they may have moved tables. My phone then rang and it was my sis-in-law telling me to leave as they are on their way to a different restaurant. I meet them about 50m from the exit and they explain to me that the owner of the place came and made a massive scene, asking them to leave and shouting to cancel the order all because my son was eating food from a different restaurant. Even though they tried to explain that the rest of us had ordered full meals and this was not affecting the bill at all. He would not have any of it and continued to rudely rush them with packing their stuff up. Needless to say, this was very embarrassing for them and affected my son as well as he felt that it was his fault. I apologized to my family and son repeatedly as it was essentially my fault that they had to experience this. However, I feel that there are much better ways of handling things and getting to a resolution without making a big deal or creating a scene, especially when there are kids involved. Not sure if this manager was going through some personal things at the time but nothing justifies the way he carried on, speaking rudely and very condescending and making my son feel victimized and everyone embarrassed. There was clearly a reason I was not meant to be there when this went down. So that being said, it's the last time me or any of my family members visits that restaurant. #primi #waterfront