Actually, the ER Drs/nurses were just going to send me home in a sling and said it will heal on it's own in 6wks. But from the Xray, I could see it was displaced, and would never heal quite right, so insisted on seeing the orthopedic surgeon (who is a friend of ours - the benefits of living in the country), and he said "80-90% chance it would heal in a sling, but if it were my shoulder I'd get it plated). As I do a lot of swimming & gyming for fitness, I wanted to maximise the chances of being able to swim pain-free again!
Yes, the OS also said nice clean break with no bits of bone floating about. Compared to other cyclists plated collar bones, he seems to have gone heavy on the screws (11 of them - most have 6-8) but hopefully that will stabilise it more.
And here is the video of the crash from my rear-facing Fly6 camera....on the easiest bloody part of the track - pathetic!