Graham Linehan is interviewed on this free to listen podcast:
twitter.com/Jarlath/status/1014201836553883648
I've just listened to the podcast, and he explained it really well. He mentions that it's not necessarily transpeople that are the problem, but men abusing the system. He talks about YouTubers influencing vulnerable children, boys winning girls races and Ian Huntley.
I don't think the host gets it. When Graham talked about the dangers to women's sport, he seemed very dismissive, but he had enough respect for Graham to let him answer.