He couldn't say what a woman is.
He is a biochemist by training and doesn't believe it's as simple as XX or XY.
He believes that some people are born into the wrong bodies.
He personally doesn't mind who is in the next cubicle, but does accept that some women might not feel equally comfortable.
He believes that the issue with men using female changing rooms is not that men might try to spy on women getting changed, because some women do that too and it's a crime that should be punished regardless of the sex of the person committing it - he clearly thought that was an absolutely unanswerable point, despite conceding he's not aware of any cases of biological women being caught spying on other changing room users.
He's not bothered that I won't be voting him because of his and his ridiculous party's views.