We know this because he eats Chipotle burritos on purpose. In fact, he's going to be eating them for the rest of his life:
Somehow I always miss these things -- this tweet is a couple days old, and you can tell by the retweets and such that it wasn't exactly a well-kept secret. But it's worth mentioning again in case a) you didn't see it, and b) you are a horrible person who likes Chipotle burritos.
Now, while I am a burrito and taco snob, I don't dislike Chipotle. Not at all. When it comes to the fast-moving assembly line they've got going, Chipotle is one of the quickest and best fast-food options out there. I've had had hundreds of their tacos because it was something I could get and bring back to my desk within 10 minutes in my last job. And it wasn't bad at all.
But cilantro is nasty, y'all. It's not just me who thinks that, either -- it's a chemical reaction that affects a portion of the population. Tastes like the devil's Irish Spring bar, it does. And Chipotle puts it into their rice for some ungodly reason.
What about us, Chipotle? Are we second-class citizens? What are we to do when we're on the road and our only other option is Arby's? Why not at least give us the option for non-sullied rice?
Also, Bryce Harper has a custom-made burritos-for-life card. I need to get famous.