At fault accident question

I know that in Louisiana if you rear end someone you are at fault, but I had a near miss this morning that raised a question.

I was on my way to work driving the speed limit (45) and there was no one in front of me. Some idiot was at the edge of his driveway waiting to pull out onto the road. I was the only other car on that stretch of road so I didn't think he'd be dumb enough to not wait for me to pass. He peels out and shoots out onto the road about 2 seconds before I pass his driveway. I went into the left lane and almost went into the ditch to avoid his stupid arse.

If I had rear ended him I'm pretty sure he would would have been at fault and not me, but I'm not 100% on that. Who would have been at fault?