If the AI is physically able to do so, it will avoid you. But if you dart in front of Latitude, she cannot slam on the brakes.
The behaviour of AI traffic was improved in V1.1 (I think, maybe it was 1.3?) but COLREGS apply, as Minime says. It is your responsibility as the person in charge to evaluate each situation and make allowance for the possible incorrect actions of other vessels.
All missions are do-able, so you may just need to rethink the way in which you do them, Capt.JB.