There’s no way inverted and non-inverted people can interact with each other
I really don’t believe it’s the kind of thing you could figure out by watching the movie ten times or looking at diagrams or animations, or even by picking Christopher Nolan‘s brain. It just flat out does not compute.
The way inverted and non-inverted people and objects physically interact strikes me as nonsensical in general, although it took me a while to figure out how to verbally articulate exactly why. Just try to explain how the fight in the hallway can occur, with grappling, pushing, and punching. (If you don’t see the problem with that, imagine a blue team and red team engaging in a round of tug-of-war. It’s impossible.)
Another specific scene near the end that I can point to for anyone who claims the interactions make sense:
So from the POV of the inverted Neil, who is initially seen lying dead before being unshot and rising to let the Protagonist in, how did he experience this? What, he goes and waits for the Protagonist to back out of the open gate...and then locks it behind him? Seriously? There’s a reason the unlocking is shown so briefly, because Nolan knows that is some major “fridge logic”, as Hitchcock called it. There are countless such scenes in the film.