“I did an interview with a guest for my podcast/film which they agreed to. Now I’m just editing and putting the interview together but all of a sudden, they emailed me and said they want a whole portion of the interview taken out. But that part is important to my film. Do I have to take it out and will I be in trouble if I keep it in?”

Hopefully you’ll have had the guest sign something like a contract when they joined your film that made it clear that their interview was part of your program which you have the copyright ownership of. But even if you didn’t, as the broadcaster of the work you will be the first owner of the entire work, including the parts of the interview with the guest. As the person editing the interview and arranging the contents of it you would also have the better copyright claim. However, depending on who your interviewee is – if they’re a famous person/local celebrity – you’ll want to have a disclaimer to make sure that your audience knows that there’s no endorsement of that person to the work you’re putting out.
Keep in mind, however, if your production needs to be insured for errors and omissions, and you have specifically been requested to take out an interview form a person who has not signed a release, there will likely be an exclusion on the insurance policy – meaning, the insurer won’t cover any claim with respect to that person who requested to be removed from the film. So, in short, always get releases, no matter what, before you record someone.
The Queen’s Film & TV Research Group are not lawyers, and this is not legal advice! For more information on copyright law, please see the Copyright Law section of this site. Find out more about Queen’s Law on their website, and Pro Bono Queen’s at the PBSC Queen’s site.