Its a live and learn situation.The ground crew had probably never experienced such a problem before.
How many times do you see racing cars pit with brakes on fire and no one gives it a second thought.
A quick peek to see if its being fueled by anything--oil etc is all thats needed ,and surely there would be a handy fire extinguisher to give it a squirt if so desired.
Leaving Sydney a few weeks ago the emergency thing went off when we were being pushed out from the terminal---------electrical fault and no one seemed alarmed.If it was at 25,000ft i for one would have had skidmaks,but after a succesful landing and at the terminal i would have kept reading my book.
If they had mentioned a small brake fire things may have been different,but with the world full of weido,s ,everyones thoughts go to a bomb or something.