Thank you for playing! And thank you once more for sharing your problem! I found the bug! One of the switches in this scene was kept ON going into second playthrough, so you got stuck with the wrong dialog for Mike and were unable to proceed. That is sloppiness from my part and I am truly sorry for that!
For you and for those who want to see both ending choices it is best to manually save near the end so it could be easily replayed.
Or, if you want to explore the game one more time, it would be best to just start a new game from the title screen (threre is no substaintial differences between first and second playthroug exept little one you might be able to notice right at the start).
First playtrough of the game must be fully functional with no ability to stuck anywhere.