Misreading someone isn't scary. It's what could happen if the man is already an asshole prior to misreading. He didn't touch her, he gave her his number.

And yes, it's serious. Some people weren't properly socialized as children, or were abused themselves, etc. Any number of things could result in an inability to read somebody properly. That initial trauma turns into social anxiety that then makes it hard to learn how to read people because that requires experience.

That inability leads to loneliness, which develops into longing for any sort of relationship, and an increased willingness to bias the meaning of these "signs."

None of this is good, nor is it the person's fault.

Men with self awareness of any kind know exactly how "scary" they are. Him giving her his number was probably the best way to go about this, giving her the option to not initiate conversation without giving away her information.

Probably falling on deaf ears, but if anything there's no need to completely invalidate OPs experience and assume he's a monster because he gave someone his number.