I've accidentally opened a camera back or two, or three, or six....with film all on the takeup spool...usually the first two wraps are totally ruined, but as you go deeper and deeper into the film wound on the 35mm takeup spool, the frames are less affected and not totally ruined. I agree, if you are self-developing, go into the darkroom, or put the camera into your changing bag with the developing tank and film spiral, and wind the film onto the spiral, then put it into the developing tank, cap the tank, and develop the film. You have little to lose, and potentially a lot to gain; maybe you will get an incredible, super-duper awesome light leak frame!
My experience is that FACTORY loaded film has one heck of a strong tape holding the film end to the spool or core inside all brands of 35mm factory-loaded cassettes of film. BULK-loaded stuff OTOH, well, it depends on who did the loading and who taped it on, and if it was taped directly to the spool's CORE of a reloadable 35mm film "cartridge", OR--if it was taped to the tag end of a once-used 35mm film that had been clipped off, and thyen a new bulk load taped ONTO the original tag...I mention this because of the photo you linked us to: that is one cheapskate way to "bulk load" and re-load a factory film load a few times...I have done it many,many times myself.