Just my two cents...
My 1st advise is to attend some Advance Defensive Driving Course like those offered by http://www.aadasb.com . You will be amazed with so much you learn and you can actually practise and experience how emergency brake and skid feels rather then really waiting for real emergency to practise your skill.
"The BMW could easily overtake us from the left since the roads had totally no cars on it but he didnt..he just kept on tail gating and flashing"
To tell you the thruth, i don't think the BMW wanted to tail gate you on purpose! If it was me or many more other experience driver, they would have done the same. The right lane is an overtaking lane. So if i'm coming real fast or faster than the front car ahead, I would have also flash my lights to warn the car ahead that fast car coming and move to the left. This actually promote safe overtaking. If all fast driver just go zig zag left right to overtake cars, this is where the danger and accident happen. And when the fast car comes near and you still not moving, we will still not cut to the left even though no cars as it is dangerous for fast cars to overtake on the left as the car ahead may also suddenly swerve left to make way. So I think the BMW DID NOT DO it on purpose to show power or what not!
"Then suddenly,even though roads were clear,the BMW jammed brake twice."
What do you expect a driver to do, when he approaches a corner? Of course brake right if speed is high! This is again a driver problem and error. Lack of driving concentration and anticipation! THe BMW driver may have just felt that he is too fast for the corner or he may not be comfortable with taking the corner at 180KM/H. He may have just brake once and then felt that he is still too fast so just brake again.
Again it was a driver error for over reacting to the car ahead because you were tailing without having any anticipation of what the drivers might do or conditions of surrounding. All this accident could have been avoided if you had been properly taught or attended proper advance driving courses.
"i dont blame my friend since he is not used to my car.He only been driving a 1.5 Stock standard wira special edition.So i guess he learnt a lesson not to tail gate during cornering."
If your friend is only driven a normal low power car, I wouldn't had let him drive your powerful EK at that kind of speed!!! I think its just insane to let someone drive a more powerful car than he may able to control!
"My damages are surprisingly quite minimal...Cost about Rm1.5k to fix."
I think you were just DAMN LUCKY man.. I have seen so many cars crashed onto the barriers along the highway to genting.
"But anyway, my question is this : When someone jam brake on you during a corner,what do you do?"
I felt it should have been an avoidance. Try to steer away with minimal steering movement and not jolt your steering hard to one side as it will just induce massive understeer or oversteer. Never jam your brakes in the corner as this will 100% cause your car to oversteer and spin like what your friend did!
"Or if you are taking one of those big high speed corners at a high speed and suddenly a Kancil cuts into your lane at 80 KM/H..how to avoid an accident?"
Again if you are in concentration and aware of your surroundings, you could have seen that the kancil might want to cut out, so way ahead if you know you are coming fast, you should have flash your lights to warn him fast car coming, like what the BMW did to u.
"lets discuss about how to avoid an accident in an emergency situation when you are speeding so that we can save the holes in our pockets and avoid injury."
Sometime it is very hard to explain all this situations to anyone. Even if you have the theory or what not, how to correct skid and this and that, ALL this are just therioes we talk about among friends, and will never be able to test or try until that real emergency situation!
And also i'm spending so much time to type all this, is because i just hope it may acknowledge one or two people in this forum and prompt them all this that could have save someone from a major accident or their life. Just sharing some of things i learn in life and in advance defensive driving courses from http://www.aadasb.com
Happy Driving!!