Originally posted by OneDumbG0
He's not calculating anything. He was going based on feeling. The only way he knew how to start unleashing his power was to goad WWH into hitting back. And he basically let Banner hit him half a dozen times to finally get that spark. The conversations with Stark and Sentry's exuberance during the fight are evidence that he believed his power would kill the Hulk. Pak also confirmed this. He underestimated Hulk. Simple as that. He didn't go into it thinking he would lose at all. If he thought he'd lose from the outset, he'd never go in the first place since he was afraid of cutting loose.
he has always been afraid of cutting loose because he felt that his opponents wouldn't survive it. it's in the nature of Reynolds to worry/fret about how he uses his powers (and how much), he tries to justify it, to use proportional force.
with the Hulk, he's quite clear about the fact that he doesn't need to worry about it and given that he did not set out to try and kill the Hulk, it's reasonable to read his motivation for the fight as being cathartic.
the statement by Tony carries little insight into Sentry's motivations, that's Tony justifying himself (yet again), because he behaves like that. taking on God's authority, for himself.
Sentry clearly doesn't/didn't give a hoot about Hulk's war with the illuminati, what Sentry did was just take the opportunity to really work out his issues, using Hulk as a "sparring partner".
this interpretation also makes sense of the "thanks" that Bob utters, before passing out. Sentry's had some sense knocked into him, as well as the stuffing socked out of him.