I learned the idiom 騎虎難下 from the famous Go teacher Guo Juan 5p. The individual characters mean:
騎 qí ride, 虎 hǔ tiger, 難 nán difficult, 下 xià down.
This chéngyǔ translates to: When you are riding a tiger, it’s difficult to go down. That metaphorically refers to something that you cannot stop once you start it. I mentioned one such example in the post about the Ellie Cup.
After White’s counter-atari at 2, I spent a lot of time considering taking at A. As you know, in the end I decided otherwise. If I had taken the stone, I would have found myself in a 騎虎難下 situation. Likewise, my opponent had also spent a lot of time on 2, for there would be no way back once Black takes at A.
I could probably escape with the corner and make a second eye. But the immesurable suffering until that can be achieved would probably not be worth it.
The decision was far from trivial: Choosing to rescue the relatively big corner means no turning back anymore, a 騎虎難下 exemplified. In the game I slammed on the brakes in the last moment and went back with minimal damage, so that I didn’t have to mount the undescendable tiger.
For big decisions like this, in tournament games particularly, it is wise to take your time. If you can afford it, leave the board, e.g. go to toilet or something.
Conclusion: In order to avoid riding a tiger, go to toilet.