I can have a huge problem even thinking straight, let alone talking, when I have a problem with anybody that requires me to challenge their behaviour. It's nothing like a meltdown, and I might not feel any physical stress, but it can be a really difficult thing to work out exactly what they're doing that I take exception to, what my rights are, and how to negotiate a solution. And I get so hyperfocussed on the unfathomable problem that my brain seems to lock up. I think I'd feel less brain-crap if I learned how to detach, but I guess my autism makes that very difficult too.