As far as pushing the button, remember the context of the time. We bombed Germany relentlessly, factories within residential neighborhoods, were in essence, carpet bombed by our bombers.
We also warned the Japanese prior to Hiroshima and Nagasaki warning civilians to leave the city. We bombed leaflets.
Prior to that we fire bombed mainland Japan, knowing the residential areas were "very flammable".
So instead of a bunch of bomber squadrons and countless more American casualties, we made a bomb that could give the same damage with one plane, with one bomb.
The dedication to DUTY was the reason that flight crew "volunteered" for that assignment, and "pushed the button".
May his family know his part saved the lives of American soldiers, and may Charles Albury Rest In Peace. Because that is what resulted from his actions.