Re: Order
Clearly, as already mentioned, JAMES GOT HIS ARM BLOWN OFF. He would've been seen to after those with life threatening injuries, because there were others who were hurt worse than him. Due to the wait time between curse and treatment, though, the dark magic in Ben's curse ate away at his shoulder and they weren't able to reattach his arm. He now has no left arm, though thank god he's still go this wand arm. He would've probably woken up after a few hours with some aches and pains, but no other major injuries, and not even noticed his lack-of-arm at first, demanding to see Lily.
When he realized he was down one extremity, he probably would've freaked out for one long, silent moment, and then made a half-hearted joke like, "Don't worry. I masturbate with my wand arm. It's okay!" Then, of course, continued to demand to see Lily. (He is secretly really pissed about losing his wedding band, moreso than losing his arm.)
Dig would have passed Dorcas over to Pepper since that's his specialty, and focussed on the others. He delegated to anyone who could help, and trusted Marlene to do what she could. He didn't waste time being polite and probably made an interesting first impression.
Later, once everyone was fixed and in the waiting stages, he would've started to clean his house and get everyone set up somewhere there, transfiguring any random objects or furniture into cot beds for people to rest and heal, etc. He probably said very little that he didn't have to, as he isn't the chatty sort.