I fell you, I'm just paraphrasing the pdf guide when I say the life of your teammate is worth more than the life of your enemy.
Were the AI above you and diving down? Maybe you were climbing while they were level? The AI use the same FM as you, so the AI only cheats in that it has perfect control of the aircraft at all times: Best trim configuration, no sporadic and minuscule control inputs or corrections, no slipping, best engine configuration for the situation, etc. Programming typical human errors is hard, and not possible for the computers Il-2 was designed to play on. However, there is a good possibility that a lot of the faults will be corrected soon by DT's work.
Even online (and in real situations) people will gladly steal kills, unwittingly or intentionally. To resolve some issues with AI, it's a good idea to try the online coops. It's nice to have human teammates, and in some situations, especially in closed-pit, it's not always readily apparent if you're fighting against a human or AI pilot.