It would be helpful to know which University is he attending in order to understand what Bogotá area he would be moving around. In general, Bogotá is a safe city despite all you can read on the internet. If you know how to move around and again, the neighborhood you are studying and Living. Another point is that not many people speak English (or any other languages) around the city. He'll be fine contacting and moving around the University. Please feel free to ask any other doubt you have.
Have a good day.