Knot comes loose?

So I've been having some trouble frogging a long dormant sock project. I brought it along to knit night with the hope that someone might have insight into what in the world I did to make this thing seemingly indestructible. Seriously, this thing does not want to unravel.

Granted, I probably created more difficulty for myself when I brazenly decided to cut a random strand from the toe because I couldn't find the woven in end. Still, you'd think that this sock would dissolve fairly easily after that, even if it didn't mean losing a little yarn in the process. Nope.

Part of the problem appears to be that the yarn split in one or two places and has created a knot in the toe decrease that I can't rip past. My fellow knit nighters helped salvage it to where the sock will rip up to this point, so there are three potential ways to resolve the matter.

One, I can finish undoing the cast on row and unravel from there. It's feasible but slow. Through this process I am learning that I'm doing good enough with working the cast on end into the project that I shouldn't have anything inadvertently coming undone there.

Two, I can keep ripping around the foot and letting the unraveled yarn pool around this one problematic decrease section. In theory this will work, but it also creates the potential for many more tangles and a rat's nest of unraveled yarn around the crisis area.

Three, I can figure out how to undo the knot or knots in the place that's the source of all this consternation. This is likely the best solution, although as I've fiddled with it since coming home, it's going to require a lot of patience.

I'm calling off any further attempts for tonight, but I'm hoping to conquer this mess over the weekend.