I disagree- accident rates are much higher for railways- it is nuts to be moving all of this oil via rail through cities and towns with limited capacity to deal with these accidents, but the politics of pipelines are toxic now so the oil moves this way until the regulations can catch up.
My guess is that the oil flash point is altered by dillutants used for fracking and/or for distribution, or the dissolved gas loads in the oil are higher. If it is due to additives, seems to me like there is some liability that will go around.