This is a situation where too much SOP prescription causes trouble. One airline will say that the CC decide which exits to use, another will say it's the Captain's decision. If time permits, as in this case, I'd say sod the SOP and brief the crew to use the main exits if they can see no threats but in this instance to keep the overwings shut, given they were above the potential fire area.
Then again, I am concerned that this evacuation seems as yet to have been unwarranted. I can't blame the crew if they were urged by the fire crew to evac, but evacuations are inherently dangerous and best avoided unless confidence is high that it is needed. Since the fire crews were there with their appliances, with a good close view of the smoking brakes, why could they not just monitor the situation, ready to extinguish and flame the moment it appeared and inform the crew that a fire had actually started, allowing them to evacuate at that point? It would have saved several injured passengers and a lot of maintenance work and cost in this case.