Honestly that's really cool about the heirloom tomato. What was the actual name of the type they were using? Some of those old varieties have wild flavors. Tbh I'm always looking for new ones to try in my garden.
Wait they didn't even tell you the variety? That's the whole point of the story. It's like saying you saw a rare car but forgot the make. Gotta be a Brandywine or Cherokee Purple, those are the usual suspects with the crazy flavor.