Mistakes like these will continue until they become costly for an offending department. Right now, mistakes cost them nothing; the only motivation to be accurate is "bad press". When jobs are on the line and/or a sloppy dept stands to lose hundreds of thousands in a civil suit, you'll see procedure get tightened up in a hurry.
Considering what's at stake, those with the power to conduct a no-knock should be held to a pristine standard of performance when selecting the target. They got the right house? No, they didn't. The "right house" was wherever the bad guy was living that night. This basically means they conducted a no-knock based on 2-month old information. That's crappy work. No excuses, no slack, no mistakes at all on a no-knock. If you want the freedom to screw up then go do something that doesn't involve authority and bullets.