March's broken arm

Why did the script call for Healy to break March's arm, and then not only not use it, but basically ignore it the rest of the movie?

Gosling never once winced or grabbed something backhanded or any of the things people do when they have a spiral fracture of the wrist! It was like he wore a cast the whole movie but forgot why. He just acted like it wasn't there. And the writer/director could have made it a part of a running joke but never even mentioned it except when March told Healy that he was going to have to do the fighting.

Never been a huge Ryan Gosling fan - his best attribute is a far-away look - but I thought he was decent in this... except for the wrist.