I have been playing for about 5-6 hours at this time and have come to the conclusion that the single player campaign of this game is seriously broken.
I have encountered serious AI issues in vehicles (especially your heli transport), I have encountered script issues where interaction with a specific NPC just all of a sudden stops, giving you no more action with that particular person.
I first thought the transport heli was ok and though i just had to make sure the LZ was an open paddock with nothing close by for him to hit. But when I would request the heli in the middle of an open paddock just to see him fly over head and try and land on the closest trees some 100m away and have the heli blow up.
I have had to reload a save countless times because of the AI or a scripting error with an NPC.
But please dont get the wrong impression. Although I think the single player is broken I have not played online as yet. I really hope that this is much better. The game atmosphere is fantastic, the visuals are wonderful but the game is (for the single player) nowhere near what it should be. Even with a 130mb v1.3 patch I still see serious AI and NPC bugs.
I hope things improve, for the single player. Can't wait to play online..