This sounds like an "I got hit by one ping and died!" AH thread.
US forces are shot at every day. It's not just one attempt a day either, it's hundreds or thousands of attempts every day. If even one in a thousand attempts succeeds, you get casualties. The same goes for helicopters. Nearly every single flight over there comes under fire of one sort or another, whether it's an 80 year old firing his WWI era rifle from his back porch, or a Syrian firing a smuggled SA-18 from the middle of a crowded marketplace. Add up enough attempts, and some of them are going to succeed.
Loudly proclaiming the ineffectiveness of a tank and helicopter because a couple of tanks were disabled and one helicopter got shot down shows a complete lack of understanding of the nature of combat. It's not just one guy with a gun vs. one helicopter in a dueling arena, where you can look at an isolated result and state that the loser sucks and the winner rules.
You'll probably never know what brought down that apache, but it probably wasn't just some guy with a rifle or even a single missile. Enough directed fire can take down any military system and sometimes the troops have to expose themselves to that kind of fire in order to achieve their objective. That's part of the nature of combat and the result of one engagement says little about the capability of either side. It can be noted however that in the fiercest fighting we've seen in a year, fighting that started off with a wave of ambushes, fighting that spans most of the country involving well over a hundred thousand combatants, we've lost a couple dozen troops, a couple of tanks, and one attack helicopter. The loss of any lives is tragic but an accountant might view that as not being too bad of a showing by US and allied troops.
Muckmaw, I'm not sure the Iraqi opponents would share your dim view of the Apache given the losses they're taking vs. their own record of successes. They're shooting at every one of our helicopters and usually not succeeding in shooting them down. That sounds like they're fairly durable to me.