I dunno if this was discussed but as i was re-reading some of the chapters i suddenly realized that in chapter http://mangafox.me/manga/naruto/v63/c601/16.html Naruto preformed a mini-bijudama with 1 hand and no clones or chakra arms. Sometimes we see Naruto appear with a Rasengan already completed holding it in 1 hand so it is presumed he made it with clones/chakra arms offscreen but this is different we actually see the mini-bijuudama still forming in his hand as he descends on Madara we see the positive and negative chakra forming all around it indicating that the jutsu wasn't finished yet but we see it finished in the next panel just with 1 hand, so what the hell just happened?
Also here http://mangafox.me/manga/naruto/v62/c598/16.html even though we don't see Naruto's entire body the top right panel shows Naruto preforming a Rasengan with 1 hand with no clones or chakra arms? O_o
This is a not a mistake on Kishis part? I do believe Naruto learned how to make Rasengan/Bijuudama using only 1 hand.. Maybe it's something he can only do in BM for some reason.
What u all think?