Kneepads of Allure when at level 8

[smoothhands]

There was a thread closed a few months back in which there was a question about this situation: you're at level 8 and use the Kneepads of Allure to force someone who is level 9 to help you kill something which gains you one level, which is legal. But then someone uses Wandering Monster to add a monster, which would then lead to gaining two levels, and thus a win.

Andrew responded:

Your helper would no longer be compelled to help, and since very few people are likely to help you if they were NOT compelled, the assumption is that at that point they can choose to wander off.

I would just like to get some clarification on the reasoning of the ruling. It seems to me that hardly EVER would someone be likely to help you for no rewards, which means this reasoning should be applicable to ANY usage of the Kneepads, not just the situation where now their help will lead to the end of the game.

The card text is pretty weakly worded about when you can't use it. It only says that the winning level can't be in a fight where the Kneepads were used to compel someone to help. It seems to me that doesn't mean you can't use them at all in this situation--only that you can't gain "the" winning level. Why wouldn't you at least be able to use the other's help to gain up TO the winning level, or collect the treasure, or at least just avoid having to run away and suffer negative consequences?