How are you supposed to learn the order of the buttons in the pirates' tower?

Solution 1:

So, unfortunately, after much searching and talking to people who know the game well, it would seem the intent is for the player to figure it out by trial and error.

It also turns out that the hint that says you don't press all the buttons is a lie. Whether intentional or a poor translation, I'm not sure, but you do press all four buttons.