To say “this seems out of line. Could it be what I think it is, or am I assuming?” By process of elimination, a person either chooses to do that, or chooses to be assumptive.
I’m assuming you’re human right now, even though the possibility exists that you are an alien who hasn’t revealed themselves as such and that your alien self prioritizes engaging here instead of talking to the world’s governments. I’m choosing to be assumptive because I don’t care to track you down and try to match your identity to a human person in real life, because I find doing that distasteful even if I never end up exposing your identity to anyone else in the world, and because I am extremely confident that this assumption is correct. But it is still an unproven assumption.
Should I hold the possibility that on the internet, nobody knows you’re a dog or alien or something in my head because it’s an assumption? Probably not. I should probably assume you are human. People will make assumptions they believe to be reasonable, and people will also call out what they believe to be bad behavior even if they’re wrong.