There never was any danger of the main gear itself failing and bringing the a/c down on the head of that poor lone firefighter, if, in fact he was too close and a little ineffective, it was because his buddies back at the safety of the pumper did not give him enough pressure. The significant damage to the a/c that resulted from the fire tells the story. Put simply; the fireys failed that test.
The whole point of the test is to see if the aircraft can cope with a wait of 15 minutes after the RTO without having to evacuate (this is to account for the delay in the fire service arriving which might occur in a normal scenario). My French is a little rusty, but at one point I believe you can hear the test pilots asking what the hell is the firefighter doing, as he is interfering with the test (no outside involvement unless absolutely necessary).
As soon as the test is declared a failure, the cavalry arrive, but mainly from behind the MLG and they're obscured by smoke.