Her own "friends" retweeting the exchange, after he had bowed out, is what got her fired. They kept sharing it with #NASA and it got to the hiring people at NASA. Hickman has come out publicly and said he didn't intend her any ill, and is in fact looking for her a new position. Only reason he even made the first comment was he didn't want her to get in trouble for using that language while referring to NASA
https://www.newsweek.com/nasa-intern-loses-gig-after-profanity-laden-twitter-spat-space-councils-homer-1084936
https://www.newsweek.com/nasa-intern-loses-gig-after-profanity-laden-twitter-spat-space-councils-homer-1084936