These people need to do more investigating. The issue is tank car availablity. The major manufacturer of rail tank cars has back orders projected at 2 years on any new order(s)
There is a specific article on this subject at WSJ. Unfortunately it is still in their Paid Subscription Only section. If anybody here pays for WSJ access can get the article and either post a copy or sumerize the specifics for us.
Here is an article that exposes the shortage but only scratches the surfaces.
The Bakken producers are facing the same issue. Warren Buffet's Burlington Northern will be making a killing for the next several years as they're booked up that far out and with producers still lining up for years out. (that's why he bought it. Plus he's big buddies w/ Obama and probably had some inkling the XL pipeline would be delayed at the least,)