They were honest tears. If they weren’t honest, Rin wouldn’t have cried and he wouldn’t have joined that relay with them– he does have sportsmanship, after all. Even though he knew the trouble it would cause to those around him… to him, it was a really important issue. How do I say this… For instance, from the sportsman point of view, you’d think he was too naive. You’d wonder why he would do that when it’s obvious that it would cause the team to be disqualified and cause trouble for the schools. But the problems of the individual can only be understood by that individual! Rin’s problems were causing such a huge swirl of conflict within him that whatever happened next could change the direction of his life. And by simply swimming that relay, he was saved by Haruka and the others… So, to exaggerate a bit, I think that was the reason why he’s able to continue living with himself now. I’m sure that all of us have those sort of painful, dark feelings that can’t be understood by others. For Rin, his feelings for swimming kept growing more and more sour, until it became this unbelievably huge issue within him. That’s why he’d lash out criticism at others, or take it out on objects because he couldn’t release those feelings anywhere else. That’s how his feelings of hopelessness were expressed in the anime, but beyond that, he was also thinking a lot, worrying a lot, and feeling a lot of distress, so– that moment when he got to swim without any cares was what saved him and gave meaning back to his life. So I think that scene gave a wonderful depiction of the theme “For the team” that this series has. Despite the consequences after that (lol).
— Miyano Mamoru, asked about what he thought about the last episode (Iwatobi Channel S radio episode 5)