The kobolds that came out were already covered in burns since they had to run in between the flaming gates.
When they saw the wall of flames appear in front of them, they couldn't help hesitating since they had been traumatized by flames at this point.
However, they also recognized that there was nothing that they could do in this situation.
Other than facing this flame wall in front of them, they could face the burning camp and horde of other kobolds behind them or face the traps that were all around them.
Compared to these other choices, the flame wall at least gave them a chance to survive.
If they push themselves, they should be able to run through this flame wall without getting too injured.
So the kobolds only hesitated for a bit before suddenly charging at the flame wall.
At this point, there were more kobolds that had pushed through the gates and were gathering with the ones that came out first.