There is no doubt that the relationship between the student and the teacher is very strong, however, I think that the relation with their friends is stronger. In order to that I disagree with the statement. Someone can consciously weigh the pros and cons of each side. The explanation is going to be as follows.
First of all, I think that the relation between the student and the teacher is limited to the classroom. The teacher can influence the students and increases their creativity and imagination in case of academic subjects, exams, researches and whatever. On the contrary, the relation with their friends is unlimited. They could be able to spend much time together outside the school building and do a lot of activities together.
Furthermore, the new technology and the internet make the student or the youngsters easily contact with each other while they are at home for example, they still keep in touch with them. Besides that, I think that the technology has a role in increasing the distance between the student and the teacher. As the internet able the student to search for information and data, that makes them depend on the technology more than their teachers at the recent days. All that leads to increase the gap between the student and the teacher.
Finally, I think that the age is a significant factor. The people have tendency towards the others of their same age. That is a great evidence of the closely relationship between the friends. For instance, when the students want to have some fun or travelling or playing sports, they call their friends immediately. In addition to that, if they have problem or if they have pleasant event, they also talk with their friends. They can tell friends everything about their personal life and their hobbies. Controversy, the teachers are bigger than the student, so, the student tends to respect them in a restricted frame.
To sum up, due to the aforementioned reasons, I think that the relation between friends is bigger than the relation between the student and his teacher.