A woman accused me of SA’ing her in front of my daughter

Long post: A couple of days ago, I took my 7yo and 4yo daughters to a public playground to hang out with their friends. She had brought a painting she drew for her friend, and we put it in a ziplock bag. I’m usually up and about with my kids at the playground, not the type to just sit at one spot. I left the ziplock bag on the bench and placed a water bottle on it so it wouldn’t get blown away. I put them at the edge of the bench so someone could still use the seating. A moment later, some heavyset woman sat down next to it. I saw it but didn’t think much of it, just occasionally checking the artwork in the ziplock. Then her companion came, and she proceeded to move over and sat on the artwork while knocking the water bottle go the ground, at which point I approached and called out “hey sorry that’s mine”. I was kind of bothered at that point because of her not noticing where she sat, so I grabbed the ziplock, which she released from under her, and picked up the bottle. She mumbled “oh you left the stuff there and didn’t sit here”. But then something clicked in her. She started raising her voice” who do you think allows you to touch my butt? How dare you just grab a women’s butt like that?” I was shellshocked. Nothing like this has ever happen to me. I was never in contact with her. Honestly, as I recall the details now, I couldn’t remember what managed to escape my mouth, but the exchange went on for a few minutes, during which her voice started growing louder. People started looking at me. I just remember the last few lines she spoke” do you want me to fucking call the police right now?” At that point, I was just too livid to say anything anymore, so I picked up my 4yo and we moved to a different play area.

The fact that she flipped the switch on me and used the victim card so smoothly, and that I allowed her to throw accusation without a proper vindication just eats at me. What pisses me off the most is that my 4yo was shaken by the whole thing. She said to me in her timid voice “Dad, is she calling the police?” I had to pretend we’re playing silly adult games with a smile. Thankfully, she has the brain of a 4yo and the moment her friend arrived, she had seemed to forget almost everything.

Why am I writing this? I guess just to get off my chest, but I also want to ask what would you have said in this situation? And since we like to go back to the same playground, if you were me and ran into the same women again, what would you say to her?

I wanted to also add I take SA seriously not just because I have two beautiful daughters, but also because SA victims continue to be stigmatized despite all the recent efforts and discoveries. This case is anything but.