Each camera was tested with about a dozen lenses each, at different FLs and distances. The method was to carefully focus manually and then shoot many AF shots with the AF sensors on the same target. The AF results were compared to the MF results.
So, using AF, the Nikon D7000 had 35.2% sharp images, 40% acceptably sharp images and 24.8% "out of focus" images. Among the lenses used was the Nikkor VR 2.8 70-200 IIG ED, whose AF samples hardly ever reached the sharpness of the MF samples.
Other DSLRs using phase detection AF did similarly poorly. The only camera which did very well, (almost 99% at least "acceptably focused") used contrast detection AF, but I won't mention which as that company never built a film camera (I highly recommend looking up the test!).
These results fit my own extensive real life experience, using both MF & AF cameras of many brands. There are particular situations where AF can have a focusing advantage as well as an undoubted production advantage, but for most photographic uses, it does *not* result in more accurate focusing, even when the sensor does try to focus on the right spot.
Remember, in the Nikon example only 35.2% of the shots were as sharp as a carefully focused MF image.
People who get their "information" mainly by reading marketing brochures may disagree...