Don't know how specific you would like to be, but the idea of BPM is to use box score numbers to predict APM (adjusted plus minutes). Can get more detailed if you'd like, but that's the important part. I don't necessarily know what was so unique about Cody's situation at COL, but nothing really jumps out as a reason to think his situation was extra favorable or unfavorable.
I just know that BPM is team adjusted and Cody had a smaller role on a team filled with older players. I thought maybe that could have made that stat look worse for him.