LeMay himself said in his autobiography ... excellent read, BTW, he was an interesting man ... that he would've been tried as a war criminal if the Japanese had won. Also, I think I had my dates wrong on the bad raid on Tokyo, I think was in March not May.
LeMay certainly was a character in a day and age where characters were prominent in war (Patton, McA and Montgomery, pop immediately to mind in this regard. Norman Schwartzkopf, for example, hardly strikes one as being of the same mold).
But he was perfectly aware of what he was doing and what he was ordering his men to do,particularly in the switch from high-explosive ordnance to incendiaries. I don't know of any commander worth his salt who wouldn't know the difference.
I guess the conditions under which that particular war were waged dictated the collapse of civilized behavior by both sides. It's just a shame it had to happen.