Glad the delt and rotators are okay anyway ...
Yep, it's not surprising to me that indistinct two-dimensional images of a lot of complex structures don't necessarily get interpreted the same way. The surgeon probably took more factors into account than the radiologist did, too. Reading imaging is an art as much as the EMG is.
What's mind-boggling to me is how they're still discovering major body structures, like the anterolateral knee ligament, and last week's announcement of the fifth muscle in what we know as the quadriceps. Medical and nursing students have been physically dissecting cadavers for centuries, and surgeons and nurses have been physically cutting into, viewing and manipulating these structures, and yet they only saw what Grey's Anatomy taught them to see. 
Stay warm!!
Speed comes from what you put behind you. - Judi Ketteler