It was stated by Zetsu who was acting as narrator on behalf of Kishi. It doesn't need the feats especially since Zetsu has proven himself to be the most accurate character in the manga, still referring to Tobi as Tobi instead of Madara.
You just take everything at face value ?
I guess you also believe that Amateratsu flames are as hot as the sun, that Itachi can fire Suitons at light speed, and that a Sage Rasengan can hollow out a mountain. Jutsu in this manga have been exaggerated before, and fallen due to the feats not matching the hype.
You claimed that Itachi's shield could repel a planet, which is absolutely ridiculous considering the fact that its greatest damage soaking feat is taking on a Kirin. Unless you also believe that the destructive output of Kirin is comparable to that of planetary collisions, even you should be able to see how absurd that claim was.
Hey yall, Itachi can beat TOAA. His shield is invinciblez !!!
On the contrary, I've read a lot of Hulk. He's been delayed by angry plants and intense flame before. Hell, he got KOed by a satellite beam at his strongest.
And Amateratsu doesn't have any feats that come even close to what it takes to actually injure the Hulk nor keep him at bay. It barely burned through Karin's shirt, it didn't get through a fodder Samurai's armor, it was slowly burning trees and the Raikage had enough time to casually slice his arm off while it was engulf in flames.
How will it delay the hulk exactly ?
As Veng mentioned, at most it will make the Hulk even more angry, which will only result in Itachi's demise happening faster.