A bit about educational methodology
Tosafot in the Bible (B. D. and not) raises the possibility that another person involved in it is a dangerous animal (and the explanation is that since it is so, then the person must pay more attention because he cannot recognize and understand the nature of fire and cannot defend himself and claim that he was certain that the fire would not spread) and therefore if it had only been written fire, I would not have learned from it a bull (because in this case the defendant could defend himself and claim that he knew his animal and was certain that it would not go and cause harm).
And then Tosafot prove from the Gemara that another spirit mixed in is not a substance but a sound (and the explanation is that if it were true that the spirit of another was mixed in, then it is not truly guilty; it should not have expected such a spirit) and according to the Talmud, if it were written only as a spirit, I would learn from it a lesson.
I decided to ask, here are two explanations that are actually seemingly correct. Another force is involved in it, it can be understood as a matter and it can be understood as a sound.
So what is the correct understanding in the end? Why did Tosafot choose the explanation that it is Kula and not the explanation that it is Humarah? How do you choose between two opposite but correct explanations?