I'll have to make sure it saves automatically there. I'm fairly sure I disabled the quit button on the main menu during this sequence but I didn't think people would force quit.
I lost my save to this very bug. I'm so fucking pissed right now. Can I get a save file file for the save point after the giant leech part? Otherwise, I'm going to request for a refund. Just did a "hate speedrun" to get back to that point. How frustrating. The 2nd time I noticed the "save deleted" message on the screen. I suggest that after this part and people quit, make the title screen slightly different to indicate that some kind of mind-fuckery is afoot.