I'm a bit mystified as to why someone who claims to be a friend to everyone would accuse an autistic person of "mansplaining" when they didn't know what you meant, attacking their gender. That's not being a friend to anyone, that is starting drama for no good reason. There's enough bullshit out there in the real world, do we really have to start on people and make more?
If someone doesn't understand you, it doesn't hurt to say "this is what I meant", you don't go attacking someone because they didn't understand you. You wouldn't want someone to do that to you, would you?