First, by talking to him, MIT would have revealed that they knew who he was. That alone might have dissuaded him, as he was clearly acting under the assumption

First, by talking to him, MIT would have revealed that they knew who he was. That alone might have dissuaded him, as he was clearly acting under the assumption that he had successfully hidden his identity (or otherwise he would not have bothered to hide his face from the camera). Second, they might have learned his motives and either found another way for him to achieve his objective (perhaps through some sort of compromise) or persuaded him to stop. Third, they could have made clear to him what the penalties the government was ready to use against him in this case were, and that they had enough evidence to take him to court if he persisted. Any of these might have been enough to lead to a less tragic outcome than what wound up happening when they immediately threw the book at him.