When you work with somebody weekly, you become involved to an extent. She's had many opportunities working with reporters. For me, it helps to see what I'm voicing 'up' on a screen. I lean over and know I can take it off the screen, turn around and sign. As a reporter, I've looked to the interpreter.
Reporters are a heck of a lot more aggressive getting information, names, dates, terminology.
In my opinion, some people have more respect for their request. Since the presenter's words are on the screen, they want to ensure it's correct. The speaker has no idea whether the information shared by an interpreter is correct because they don't understand signing. And the whole room may not see it. I urged her to share something she didn't like.