If Tom was being interviewed and in the middle wanted something “off the record” could he do that? Like during the interview say, “strike that from the record” and the journalist can’t include it?
He can ask and most journalist would probably oblige if it wasn't being used as a tactic to worm out of something already agreed upon. But typically, ground rules should be established by his publicist before the interview. So, hard time stops, off limit topics, whether portions of the interview will be on background or on record, etc.
And once the terms are agreed to and the interview starts, all things would be considered on the record. But if Tom realized he made a mistake and spilled something he wasn't supposed to, like a major Spiderman spoiler, most decent and ethical journalist would absolutely oblige and not take it to print.
However, a journalist might include what happened in their story, sort of like a pulling back of the curtain if you will. So they may write something to the effect of:
"In the course of our discussion, the actor lived up to his spoiler of spoilers reputation by revealing what can only be described as a huge third act event that would send audiences reeling. Immediately he realized his mistake and asked that I not include it in my story. I happily obliged."
Of course, celebrity interviews aren't hard hitting journalism and these pieces are done with the intent to puff up the actor and sell a product. So there's certainly a lot more leniency than say an interview with a world leader.
At the same time, if an actor is being really disrespectful or refusing to answer any questions, the journalist absolutely will print that and likely won't be as willing to honor any special request from the actors publicist after the fact.
