WATCH: CBS Reporter Accidentally Witnesses Illegal Border Crossing, Gets Threatened

Last week, CBS reporter David Begnaud posted a video online of his tense encounter with a human trafficker at the southern border as he witnessed two migrants guided across the Rio Grande "in broad daylight" just a few hundred yards from a border checkpoint.

Begnaud — whom John Sexton notes is the same reporter who debunked the false claims about the iconic "crying girl" photograph — went down to the border at Roma, Texas for a story about plans to survey the land for a future security fence. Stationed at a "lookout point" near a U.S. Customs checkpoint, Begnaud and his producer drove over the international bridge to the Mexican side of the river, leaving the camera crew on the American side.

That's when Begnaud witnessed a smuggler using a raft to deliver two people across the border to the American side. When Begnaud began to film the illegal crossing on his cell phone, a "scout" approached him from his right, threatening that he was "not safe" and needed to leave, which Begnaud caught on film. The threats from the trafficker grew intense enough that Begnaud and his producer became afraid for their safety and headed back to the border checkpoint.

The illegal immigrants successfully made it to the American side and disappeared into the woods. As he crossed back to the Mexican side, the man guiding the raft gave the CBS team "the finger," noted Begnaud.

The incident took place during a shift change at the checkpoint, the human traffickers routinely timing their crossings when they're less likely to be spotted. Begnaud underscored in his report that this all went down "in broad daylight" and with little effort from the traffickers, who were able to simply walk right across the river.

"This is an example of why the Trump administration has been pushing for a border wall," said Begnaud.

Begnaud tweeted out some of the footage and a summary of what took place, and then followed that up with a full report . "Today, on assignment in Mexico, producer Mark Hooper & I saw a 'scout' guide a smuggler across the Rio Grande, in a raft, to deliver 2 people to the U.S. who entered illegally right near a legal border crossing," Begnaud wrote. "The scout threatened us."​