No doubt, those Soldiers there failed to properly clean their weapons in a combat zone, but then again, it's difficult to do this while on the move in such a storm. A clean weapon is dirty again in only a few minutes. What means could be designed in by the manufacturer to prevent a total failure under those circumstances?
It appears to have been much less a matter of the failure of the individual weapons than that of the unit's crew-served weapons not working when they needed them. That appears to have been a matter of three factors: rust on the gun mounts on the vehicles themselves, pretty unforgivable for a maintenance unit, combined with weapons in deplorable condition because their vehicles had been pulling other wheeled vehicles stuck in the sand out for some 14 hours previously, resulting in a frosting of sand and grit on everything, and some exhausted troops who had overlooked maintaining their heavy weapons, though some may have taken better care of their personal ones. And of course, they were hit in an ambush, surprised while emotionally and physically exhausted, not the best circumstances for combat arms troops, much less a support unit with limited warfighting capability.
Not all the fault was with their weapons, nor was it necessarily *just* one of leadership considering the taskings the unit had been given and had accomplished. But had things been done a little differently, they might well have come out better than they did, driving off their unsuccessful attackers and regrouping to treat their casualties with fewer or none of their own taken POW. That's the lesson for other support troops who figure it can't happen to them too, or at least likely won't. And indeed, for most of them, it won't, but that's little comfort for any who do reprise the same story.
Don't forget the eight who died to provide the object lesson: CWO Johnny Mata; Master Sgt Robert Dowdy; Sgt. Donald Walters; Sgt George Buggs; Spc. Kiehl; PFC Lori Piestewa; Pvt Reuben Estrella-Soto and Pvt. Brandon Sloan.
Mourn from them and regret their loss, but don't overlook or gloss over their errors, or they'll be repeated and the lesson they learned the harrd way will have to be brought home again.
In that regard, what CAN be done to sandproof a rifle, at the design phase?