On the first round? Not bloody likely, unless she ignored all her training and rode the bolt forward...
I was wondering about that myself. It is possible to have a malfunction or misfire on the first round. But I wonder exactly what it was. How was she riding? With a round in the chamber and weapon on safe? With a magazine loaded but no round in the chamber? What exactly? It could be that she never even charged her weapon or in the confusion never took it off safe. If her weapon "jammed" maybe she had her magazine loaded with thirty rounds instead of 28 and had never stretched her magazine spring? Could be that first round hung up in the magazine, never getting fed into the chamber or something.
Still, she should've performed immediate action to correct that malfunction. There were other stories of weapons on that convoy failing. SAWs, .50 Cals, M16s. It sounds more like no proper maintenance and poor training with the weapons to me.