An episode of the IT Crowd had a B story that was kinda transphobic. It was minor enough and the show was popular enough he probably could've easily just apologized and that would've been that. But instead, in 2013 after said episode was brought up and criticized for being transphobic to the creator, said creator tripled down and became a full on anti-trans "activist" who makes even JK Rowling seem benign by comparison.

Graham Linehan is a prolific transphobe

He's also actively picking fights with supporters of trans and non-binary people, such as recently David Tennant of all people.