I've had my share of those kinds of interactions.
One approach is to adjust your language to something that cannot be argued with.
Your things can't be in there.
There's nothing about shoving vs placing, or even who put them, just statements. This is really hard work and not my first choice. Sometimes if I get your sort of response I might adjust, so I would start with "you can't just shove your stuff in there" and when I get "I didn't shove..." I could say "that's not the point, your things can't be in there."
The other approach, for someone whose age and mental capabilities make it appropriate, is to talk (at first) the way you would with anyone else, and then when you get this pushback, go meta by discussing the conversation and word use rather than the stuff and where it can be:
Come on. You're twelve years old. Do you think that placing them there makes it ok? Place, shove, your stuff can't be in there. Move it.
Come on. You're twelve years old. Your stuff is crumpled and hanging out like it was shoved in. Put it away properly.
Do you want examples because you intend to lawyer at me and prove you've done nothing wrong, or because you want to understand the situation better?
Essentially be prepared to lift yourself up a level from the conversation to get to the real point, rather than staying at the level of the original plan for the conversation.
I had two kids in my life who used to do this to me. The first, who I loved (and still do) I would say "you're going to be a great lawyer some day!" and stay mostly in the first mode to minimize the arguing in my life. The second, who I liked at first and grew to detest, eventually banning her from my home (she was a friend of one of the children's) I went mostly in the second mode with. Everyone else in her life backed down when she did that sort of thing, her intentions weren't generally good (she's the most selfish person I have ever met) and she could find a sticking point in any sentence no matter how neutral. So I generally called her on it. Oddly, she liked me (for her definition of like) for far longer than I liked her, so calling her on it doesn't seem to have been a problem.
You have my sympathies because this can be exhausting. I raised my kids that they can ask for a reason on a decision so they understand it. When this kid was around, "why?" was always so they could argue, generally by contradicting: "but we won't!" "no it isn't!" and so on. So tiring. I had a set phrase for her which is "I've explained my reasoning to you and I'm not open to changing it." I don't think I would have done that to my own kids, but they didn't drag me down with lawyering every chance they got.
Another thought. Once conversation between the two of you is relatively normal, do take a look at how you talk. Some people (and I have no information to know that this applies to you) put unnecessary "color" into their conversations that can offend other people. For example, if A doesn't belong in B but was put there nicely, saying "Don't just shove your A sloppily and lazily into the B and think you can pull it over on me" (to exaggerate.) If you think this might be you, luckily the advice is the same: focus on simply stated facts like "your things can't be in there." I only mention it to alert you to the possibility that a conversational habit that triggers defensiveness, argument and pushback from this child could be having an effect on others who don't react to it but still don't like it. There's an opportunity for you to think about how you talk to everyone hidden in this hard-to-deal-with child. That said, I don't think the majority of such situations arise from the wording choices of the person getting all the pushback; I just wanted to mention it as a minority possibility.
