I disagree with "the listen to your doctor advice".
This is a case were your doctors interests do not align with yours.
A 1/10,000 chance of getting sued for the doctor- is worth more to your doctor than your entire triathlon career.

This is one reason why so many fat and unhealthy people have doctors that forbid them from exercise. (From the doctors perspective there is little to gain).



I say listen to your body and use your brain.

Riding on a trainer, running up hill in a sling, or swimming with only one arm- is less stressful on your shoulder than a whole bunch of things that you will do accidentally.

Which is more stressful for a healing collar bone?
Running up hill on a treadmill.
Or walking quickly down a flight of stairs?

Riding on a trainer?
Or driving your car on a bumpy road?

How do you know?
Well- which hurts more?

Lots of pain is bad.
A dull ache probably means the bone is healing.