According to Tosfos' understanding of Rashi, what is the case of the mishna (based on the braisa) of Shum Kesef, and what is the halacha?
Avi Lunger, valley village California
Tosfos understands Rashi that both directions of damage happen, and brings several questions and therefore chooses to learn like Rabeinu Tam who learns about two separate cases of damage.
The Shitah Mekubetzes brings many Rishonim at great length who discuss different possibilities in Rashi, whether the damage is at the same time or one after the other, with its problems. One cannot know for sure what Rashi meant, as some even explain that Rashi is saying like Rabeinu Tam!
It is clear that the Halachah is always that the value of damages counts and is subtracted one from the other. See Shulchan Aruch, Choshen Mishpat 389:13-14, 17.
All the best,
Reuven Weiner