No, manga creators have no say over what animators do with their story, the animators buy the rights to animate it, and it's basically just the manga creator hopes the studio doesn't mess around too badly with their story. Japanese people don't file lawsuits like Americans do. If they are really annoyed about what the studio is doing they will make some comments- like Kishimoto did (in a subtle way, for westerners, in as blunt a way as one can be without being outright rude in Japanese culture) at Jump Festa 2009 about the naruhina/Hinata worshipping and antinarusaku/Sakura bashing amongst the fans, and made it clear it wasn't from anything in his story- thus pointing straight at the animators, and they knew it too, because they pulled stunts that further overplayed Hinata and minimized Sakura during the Pain arc.
Now I don't think he minds the narusasu stuff as much, and in fact has put in things that does hint that Sasuke does harbor some romantic love for Naruto, but because of that, that makes his hatred all the stronger for Naruto- because he knows Naruto could potentially draw him away from his headlong plunge into psychotic violence directed from his hatred for everything.
There are basically two factions at Studio Pierrot, one that tends to work with canon and writes the more canon-like characterization of Naruto and Sakura (last week's episode was done by them) Then there is the faction that point blank admitted they worship Hinata (they also worship Sasuke.) They wrote this week's episode. Not only is there the problem with their Hinata and Sasuke worshiping, but their writing skills are significantly lower as well- it's this faction that writes the worst cliched filler characters, that overplays Naruto's loudmouthed stupidity and Sakura's part 1 Sasuke fangirlism, and her tsundere tendencies in both part 1 and 2 and underplays her canon romantic love for Naruto.
Interesting stuff. Cultural differences in handling things are so easy to forget. Thanks — your info is often enlightening!
As far as the NaruSasu stuff, there is at least some ridiculous manga precedent set — the kiss in the classroom, even though it wasn't at all meant as yaoi. Kishimoto is at least making light of it their close relationship. But the NH shippers seem to be much louder than the NaruSasu ones, even though there is no support. (Meaning he's never had a single romantic anything with Hinata, mistaken or otherwise. And he has with Sakura and Sasuke. Imho, the manga would go NSasu before NH.)
But aside from all this, I think that extreme characterizations of the anime and the blatant competition for Naruto's love interest, when there is none in the manga, is simply better for the tv audience. Whether the animation team are NH shippers or not. But you're right, with this episode too, where Studio Pierrot is involved, they seem to distort things to the worst degree. I just can't help thinking it's an easy way to stoke the fires of an unseen audience. Instead of telling a good story, they are just stirring up people's reactions, running through the checklist of fanservice items, to keep people watching.