But after Trump's campaign manager, Corey Lewandowski, was charged with battery for grabbing Fields's arm and dragging her out of the way, Trump was forced to migrate from his untrue original position -- that it didn't happen -- to a new one: Lewandowski was trying to protect me.
CNN's Anderson Cooper asked him about it during a town hall on Tuesday night.
"She went through the Secret Service," Trump said. "She had a pen in her hand, which Secret Service is not liking because they don't know what it is, whether it's a little bomb or..."
Cooper cut him off, which is a shame because: A little bomb? This was Trump's new argument -- that maybe Fields was a threat because she had a pen that freaked out the Secret Service because they didn't know if it was a bomb or not?
This seems ... unlikely. So I reached out to Matt Barnett, proprietor of Bonetti Explosives in Columbus, Tex., for nearly a decade after having done contract explosives-removal work for the U.S. military. Oh, and he's also the former star of the Discovery Channel show "Fire in the Hole," in which he blew various things up.
Barnett hadn't heard about all of the stuff with Trump and his campaign manager.
"It sounds kind of crazy to me," Barnett said to start, which is fair. "But an explosive device doesn't have to be very large to kill somebody."
He noted an incident in 1996 in which a Palestinian bombmaker was killed after Israeli agents put explosives in his cellphone. "That device was so small -- keep in mind it was right against his head -- when he was talking on the phone it went off and the back of his hand was perfectly fine," Barnett said. "But half of his head was gone."
There were also pen-bombs during World War II, used to trigger larger explosives. Which brought Barnett to blasting caps, which are about a quarter-inch in diameter and a few inches long. Those caps include about a gram of high explosive -- an amount the size of a pencil eraser. An explosion from that, he suggested, could seriously injure someone or maybe even kill them. There exist pen-shaped triggers that can be used to set off explosives that could potentially be modified to do the trick, though he was quick to add, "I wouldn't want to tell anyone how to do anything." (Which also made me realize that doing a Google search for "bombmaking" probably wasn't the best decision I made today.)
"It's not outside the realm of possibility," he said. And then he added: "I mean, it wouldn't be the first thing to come to my mind if a reporter was coming to me with a pen? I mean, that's kind of what they do, right? It wouldn't be my first thought to think that that's a device, but it's not outside the realm of possibility."
Which: Of course. No one would think that Fields was holding a bomb, and there's no evidence that Trump did either. In stills from taken during the incident at the event venue, you can see Fields (light-colored jacket) approach Trump to speak with him. Trump sees her and walks with her a bit, despite his apparent terror that she was trying to bomb him; in the bottom frame you can see Lewandowski, with close-cropped hair, reaching in to grab her.
Oh, by the way: That guy with the arrow next to him? Secret Service.
He didn't seem very nervous about Fields either.
Here, let a small child teach you how to make a pen-bomb for April Fool's Day.