I get it. She overreacted, and definitely shouldn't have been still thinking about it, but I've had it happen several times where someone has insisted on buying me a drink, and then they feel like they have a right to kiss/grope/fuck me because they spent $5 on me. They try to tell me that I OWE them. This has happened often enough that I don't let anyone buy me anything (even dates/boyfriends) until I can trust that they're not trying to coerce me into something I don't want to do and that they won't react with rage or violence if I don't want to be physically intimate. Me refusing to let others buy me anything is a way that I can keep myself safe.