I don’t see any issues using this code since it is publicly posted and is available to all teams. A lot of good teams use OkapiLib which can give a much more of an advantage and it’s perfectly legal. Using code that is only available to some teams is what violates <R2>, because it gives your team an unfair advantage over other teams that don’t have access.
I’m not saying anyone should or should not use this code, that’s up to you to decide. Generally, you should try to understand the code you are using and not just blindly add it to your project, and always credit the author/source. All I mean to say is it does not violate any rules. There is value in both learning how to write the code yourself and in learning how to work with code written by others, you should find a good balance.