[paulgerhardt]

I’m sure I’m missing something here but isn’t this common knowledge in sailing and climbing?

Specifically tying a knot with opposite chirality to one existing on a line can cause both knots to capsize and roll out.

One would not take it as given that three knots plus three knots would yield six knots in this scenario.

[3cKU]

It does seem the obvious place to start looking, and the only surprise is that it took so long.