Mark Ruffalo’s signature character assumed that he’d be able to survive the radiation from The Stones, given how infused with Gamma he already was.
While all of the surviving heroes participated in the Time Heist and should be thanked for bringing back half the galaxy, Smart Hulk was particularly instrumental.
Banner was the one who physically wielded the Infinity Stones and snapped his fingers, thanks to Tony’s nano gauntlet.
He was ultimately correct, but his arm was permanently damaged as a result.