After gym class ended, everyone went to their next classes and news about what happened spread around the school. Of course, the story became more and more exaggerated until the version of Tommy transforming into a monster and trying to kill everyone in the gym became the normal version. For the people who actually witnessed it though, they still spread the original version.
At some point, the exaggerated story calmed down and the real truth was out. Everyone just felt like Tommy overdosed on something he shouldn't of and that is what caused him to go nuts. As it was, by the end of the day, all final classes had posted memos about the dangers of drug use and how it would impact your lives and destroy your future and yada yada yada...
Since the school was sticking to this story, it made the true story seem much more believable. As such, by the time everyone left, even though people were still talking about things, it had calmed down.
