K-5 iso 6400 performance, could it be?

hey guys,
can you pls take look to iso6400 shots in this page; in below review?
http://www.adorama.com/alc/article/Product-Review-Pentax-K-5

there is one child/baby picture with , f around 5, and iso6400
could it be true?

lens is not a price 50-200 f4-5.6 with below average optical quality (ref http://www.photozone.de/pentax/138-pentax-smc-da-50-200mm-f4-56-ed-review--test-report?start=2 )

so how come this can happen?

also ther is aone lady portrait with iso 6400 with same lens, i could believe if he says iso 400 easily..

i have K-5 with 18-55; whatever NR level i apply, my pictures are not even close to these samples, maybe with 1600 iso, mayyybeeee... whereas he shots with 6400 with a low grade lens,
something wring with me?
something wrong with information in the review?