Re-fixing and re-washing won't harm your film, just do it as normal, agitate the fixer to make sure it gets to the rebates, wash and dry as usual. There's some possibility that the fixer can start dissolving the shadow details on the negative after a few hours in the fixer, but that won't be a problem here.
Drops of water inside the tank could cause condensation on the film, as could a change between warm and cool environments (outside to inside, warm bathroom or kitchen etc). It's possible that condensation formed on the film stuck it to the spiral, stopping chemicals getting to the surface. I've sometimes left film undeveloped in tanks for several days and haven't had any problems. That's the only thing I can think might cause this.
Cheers and good luck,