Moin chris,
I guess you are looking at the new AH Plane Statistics.
The difference between kills and deaths is easy to explain: Unlike the old "Kill stats in an expanded format", Ship Guns, Gunner & Chute are missing on this table. But deaths by them are still factored into the total deaths count.
Ship Gunner, Gunner and Chutes have currently ~30 000 kills total - and that's the amount of kills missing on the new AH Plane Stats tables
Detailed example:
Right now, B-24's show 13466 deaths in the "All planes" stat page. I click on the deaths number to get a detailed breakdown. The bottom of that detailed list now tells me 13469 deaths (kill stats are update real time, so the death toll is slightly higher now). But when I manuall add up all the "deaths by" I get only 12232 deaths.
Using the old "Kill stats in expanded format" those missing 1237 deaths can be completely explained by "Ship Gunner", Chute & Gunner kills on the B-24.