if someone decided I was toxic, and went NC, my attempts to make contact with the person who (to me) had inexplicably vanished from sight, would be construed as 'trying to reel them back in for more abuse' etc.
My feeling on this is; if someone is toxic, they will not respect the other person's wish to not be around them.
If someone disappeared from your life, and was cagey or ignoring you repeatedly, then my guess is that you would just ask; is there something I've done?
If they came back to you and said 'yes, you've been trying to control me as long as you have known me. I find it really difficult when you step in an insist things are done a certain way. You aren't interested in me even remotely; I feel you didn't even know what I'm going through. Every time I suggest something different, something for me, you cry and make me feel so guilty that I end up trying harder to please you. In short, I'm feeling as though I'm being pushed out of myself because I'm so caught up in being the person you want...'
Well, you'd be hurt, obviously. What happens after the pain is what counts though.
If you were toxic, you might find yourself having panic attacks that they really should know about, or having a heart tremor that needs investigating so they'd come back and help you through that difficult time. (My dad's mum has had two weeks to live for 3 years now. He's contacted everybody to ask them to tell me that I must visit her, it's real this time, she's about to die...') In short, you'd attempt to manipulate the other person into coming back to you. That's what toxic people do; they manipulate other people in order to get their way.
Then, the chances are you'd conveniently forget that they ever pulled you up on your behaviour. It simply didn't happen. Everything's fine and always has been. You are wonderful.
If you were non-toxic, you would sadly agree that the person didn't want you in their life and you'd let them move on and you'd move on yourself.