OSB - the doctors onshore (who are the ones who make the decisions since few vessels have their own on board) will always err on the side of caution when there is a medical emergency at sea.
We also do not know the actual extent of his injuries nor any other medical condition he might be suffering from (and he's not the youngest of seamen either so that might have played a part in the decision).
The reason we train hard is so that this sort of stuff is routine, even if it looks dangerous and impressive to onlookers and is also an explanation of why winchmen are volunteers.
My only (minor) criticism would be that the winchman probably should have come up with the stretcher - just in case they ended up in the water, as a casualty with a broken arm strapped into a stretcher has no chance of survival if the winch malfunctions or the aircraft has a problem requiring the cable to be cut. However, that would require the vessel's crew to be trusted managing the hi-line during the recovery.
Nice to be able to have enough assets to send a second helicopter and a fixed wing for top cover!