I just discovered the weirdest bug! (found only in Singleplayer/COOP and involves the bots)
I found this bug when working on my hand held guided stinger. Apparently bots can enter a vehicle even if a person is still occupying when they are currently in control of a launched vehicle. For example, if you launched a guided SA-3 missile, normally the SA-3 launcher vehicle it self is still locked out from other players. However Bots seem to have an overriding factor and can enter it anyway. (though the AI code for the SA-3 makes it very unlikely that this would ever happen.
This will also apply to soldiers since the game treats them similar to vehicles but just with special stuff like walking and such.
So when I fired a guided missile from a handheld launcher (which means I am NOT in a vehicle, doing this as a soldier!) I return after using the missile up to find out that I have literally possessed by a bot! I couldn't control the soldier anymore! The only thing I could still do is enter vehicles (if the bot takes me near one) or change weapons/use parachute. I can move around a little bit and sometimes the bot might decide to go in the direction I want to go, but most of the time the bot has total control!
I was freaked out, since I was not expecting this and my soldier had a mind of its own.
However, if I am lucky enough to be near a vehicle, I can enter it and after that it seems the bot has no control of me when I'm in a vehicle. However the bot will still be in control once I leave the vehicle.
Only bad side is that the game will CTD if I die or if the body that the bot left dies (as in the bot will actually leave an occupied soldier body behind when he enters my body) This game needs an exorcist!
I dare someone who knows how to fire vehicles from the stinger weapon (or the RPG launcher) to try this themselves! It will take quite awhile before it happens but it will. First make sure you are near a idle bot or a known spawn point where they will spawn. (the bot MUST be idle! If he is walking to a vehicle or engaged with the enemy then it is extremely unlikely he will enter your body) I recall a spot right next to the flag at East post in El Alamein to be a good place to try this.
Once you are in position, fire the vehicle and you will be flying/driving it while leaving your body behind. Given enough time and some good luck, a bot will either spawn next to your body or the idle bot you chose will enter it. When you leave the vehicle and return to your body you will find that you have been possessed. After which you will see the body the bot left behind and will have extreme difficulty moving around on your own, since the bot won't let you do much. You can change weapons freely and enter vehicles if your near one, but aside from that, the bot has free reign over you. However if you die (or get killed as a result of the bot making a stupid decision as all bots naturally do), then the game will crash. If the body the bot left behind dies, then the game will crash.
So far I've managed to get possessed by a bot twice. And so far it seems to take awhile/take some luck for it to happen.
I wonder why a bot can get in a used vehicle like this and not a human player...hmm....