Atti and I went to the Ortho clinic yesterday and all is well. They did an X-ray and we saw an Ortho registrar and he was happy with where the arm was, no need to raise it in the cuff. He explained the break to me (everything single thing the Wook family have been saying about the X-rays turned out to be wrong, ha!) - it is a small fracture across the front of the humerus, with no dislocation. I told him that Atti is using the slung hand to do things and sleeping face down and he basically said that it was all fine, so long as he didn't straighten his arm while it healed it would be all good.
So that is kinda awesome. But there will be no getting the cuff wet, so no baths or sprinklers or whatever. So I have to figure out a way to deal with his hair.
And he said at this age it will take 3 to 4 weeks to heal, so it should be off and done by the end of the month, in time for school. Hip hip hooray.