True, but even though Steve wasn't hands-on with the Academy he would certainly have been paying attention to it and its students. The whole AVENGERS ARENA and AVENGERS UNDERCOVER incidents would also have given Cap extra reason to be aware of Hazmat. And then after that when she was working with Tony Stark (who was helping with her containment suit problems) and then with Carol, he would be aware of her progress and development through them as well.