Am i at fault (CAR ACCIDENT?

A week ago, i had a car accident. I was going up a hill with my car and it was also a curve, as i turn the curve i see a big truck on the side of the road with no directionals on. i figured it was parked there so i continued to go. however as i approach the truck, it head begins to turn toward the left blocking the road. there i realize i was going to crash. i rear ended him trying to avoid collision otherwise had i gone straight i would have hit the cabin where he was or had i gone to the other lane and try to overpass him by accelerating i could have crashed head on with another car coming the other way. did i do the right choice? any help is appreciated