I'm not really surprised that a salesperson might not have any clue about saving and sending pdf files, let alone being able to get a screenshot, save it, then send it. There are more of these inept people than you'd believe.
A few years ago, I worked with a guy who was a technical writer. Granted, he was probably in his early 50s. He lost a file he was working on, so I tried to help him. Apparently, he thought he saved the files in "Recent' but couldn't find it there (apparently, he had already opened more than 10 files, which was the setting for the Recent listing in Word). Seriously. He had no concept of file structure/saving. So I asked him to go to his desktop and, I kid you not, he started looking at his desk. I said on your computer. He was lost. He had no idea what I was talking about. I was shocked. And he wasn't kidding.
Lots of people in sales have very little computer knowledge. There are many who do, but many who don't.