Another small irritant about this scene, in a movie that I otherwise love: Why didn't the Enterprise just pummel the Reliant with photon torpedoes and blow it up quickly instead of crawling away? The Genesis torpedo was clearly not ready to detonate since it was on a "build up", so it couldn't have been prematurely triggered in the process. Otherwise Khan would have rushed it himself. No one would have had to go into the irradiated engineering room. I think I just answered my own question there.
This thing can create planets.
Best thing is just to get the hell out of there.
A couple of Photon Torpedos aren't going to do too much. We've no idea what's inside. Firing torpedos might even set it off.
I did once wonder whether you could beam over to the reliant and then beam out the genesis device to the limit of the transporter range in the opposite direction to buy you extra time but you might not be able to get a lock once the device is active.
Damn, I've not over analysed this stuff for a while...