This makes a lot more sense now in the context of what Sean says later about Billy comparing Addario to Sullivan.

One sentence that I keep getting hung up on
It's hard and cold and it's like the rain his leg, his arm, everywhere he can still feel, tells him is coming that just won't come. I had to read it twice when I did my initial read through and still stumbled over it this time. I love the imagery though and it could probably flow a wee bit better if there was a "that" between "the rain" and "his leg".