Pesik Resheih DeLa'Avar (inevitable consequence relating to the past)

Question

The RaM"a (Y"D 87:6) cites an opinion that one may shouldn't stoke a flame beneath a non-Jew's pot, for fear that there's some milk and meat residue in it, and you might come to cook said milk and meat residue.

R' Akiva Eiger there asks why this should be forbidden considering that there's really a doubt if there is any residue and you don't intend to cook it if it's there. He answers that it's a Pesik Resheih (inevitable consequence), and the doubt relates to the past (whether the pot has milk and meat residue from previous cooking), not purely to the present/future (whether your action will cook meat and milk together), and in that case a simple Safek (doubt) isn't enough to overcome the defining characteristic of a Pesik Resheih, which is its inevitability.

(Pesik Resheih is confusing enough without adding DeLa'Avar to it, so I hope the above was clear.)

If this is so, are there other cases like this in which a Safek DeLa'Avar is deemed inconsequential, and a Pesik Resheih is declared and said action is forbidden? Are there any cases that contradict this (either within R' 'Akiva Eiger's own writings or just in rulings by others who don't hold this opinion)?

Answer 1

The Achronim (Shulchan Aruch OC 316:3) deal with the case of closing a box on Shabbos when there might be fly in it: Safek if there will be a definite Melacha of trapping. I believe there is a large Machloket there between the Achronim, with the Taz famously permitting closing the box.

See also the Gemoro in Shabbos 41b about allowing someone to put cold water in a pot that might cause the pot to become stronger and you will be Mechuyv in Meleches MeTzaref. The Gemoro says Rabbi Shimon is Matir because it is a Davar Sheeina Miskaven. Tosfos there says that is therefore not a Psik Reshe becuase if it were Davar Sheeina Miskaven would not help. Rabbi Moshe Feinstein on his Peirush on Maseches Shabbos says that the reason why it is not a Psik Reshe is because it is doubtful whether the pot really reached a hot enough heat for cold water to soldify it. Rabbi Moshe says that we see from here that even though the Melacha in the Safek is only in the past, it is still good enough not to be considered a Psik Reshe.