Elphaba was more than ready to do something horrible to the man when Fiyero decided to intervene and send the man on his way. Oh that really got under her skin. She didn't need help and she sure didn't need anyone.
"I don't need you. I don't need anyone. So just leave me alone and let me go on my way." Which was about as diplomatic as this Elphaba got. She turned her attention elsewhere, trying to figure out where to head next. It didn't bother her that her skin color made her stick out, and she could handle anyone that tried to confront her about it.