The fact this was paid off, and paid off so rapidly means that targeting major infrastructure for massive payoffs is going to become more and more prominent. The next time though, it'll be $50M. I work with people in the oil fields and I know the numbers they are playing with and the fact that a single well being down can easily be $100,000 lost per hour. So obviously they want these systems back up fast.
$5M for shutting down that major of a pipeline seems like too little, unless, of course, they weren't expecting the company to even pay. Now that these actors know that the oil (and quite likely other utilities) are more than willing to pay big bucks to get back online, they will be targeted far more.
There are so many reasons this is very very bad.