There seemed to be more going on with the Trauma example than just a pure radiation drain. Lord Armageddon noted that the previous fuel source for the machine was "Soul Man" and he could be used because of his powerful life force. True, "Soul Man" got his power from something Leader did to him with gamma radiation. But, we've seem Hulk COMPLETELY drained of ever bit of gamma radiation in his body, so if the Trauma thing was supposed to have killed him it was more than just a pure gamma drain. However, it's a fair point. With the second time Rulk tried draining him, it wasn't long after Hulk had gotten his power back and had taken in the massive amounts of gamma radiation that turned all the heroes into gamma beings. So that was Hulk with a lot of extra energy. I'd wager that given the massive amounts of energy that that we've seen Thor capable of absorbing and containing in Mjolnir (the Kree Nega Bomb comes to mind whose energy was used to reignite a dead sun IIRC) I just don't see Hulk laughing it off.