Yep, that's a bug. Turns out the condition that's supposed to lock you out of that branch doesn't actually get checked. Whoops!
You could un-brick your save file by opening it in a text editor and setting one of your skills to false, that way you can get past the screen. (Or start a new one.) In the meantime I'm going to push a hotfix for the web version, since that's a game-breaking bug. Sorry and thanks for the report!