Hmm I think it’s the other way around. I find it’s usually the case that stuttering is mislabeled as mild error prone speech as you’ve called it here. People recognize that it’s common for neurotypical people experience errors in their speech when they’re stressed, overly excited, nervous, scared or caught in a lie. This is due to the fact that the emotional part of brain is connected to the speech area in all human beings. Therefore when people sees someone stutter, their mind doesn’t consider that that person might have a speech disorder because it’s the farthest thing from their mind. Or they may not consider stuttering as a speech disorder because they don’t really know much bout it. Only what they’ve heard or seen on the media.