Ah hell nah, with that kind of explanation, he genuinely is just playing with her. Just because of a few months of internship so he decides to spout out that crap that would clearly hurt her like that?
Bro is just putting scars on her for no good reason. She'll develop trust issues with the people she opens up to.
I hope and pray she does not let him back easily. Don't be a pushover FL. DON'T disappoint me.