Rebbi Akiva Eiger [דרוש וחידוש] asked on Tosfos from the gemara in Sanhedrin [9a] that if the father of the girl who was accused by her husband's witnesses of unfaithfulness, brings witnesses who made the עדים into עדים זוממין, the law is that they are killed but need not pay. This is despite the fact that they plotted to obligate the woman both capital punishment and the monetary loss of her Ksuba [some people prefer to say "Ketuba" and that is cool too!!]. But according to Tosfos who said that when the עדים attempted to make the accused liable to two punishments they also receive two punishments, in this case the עדים should also get מיתה and have to pay - a double whammy. Why don't they??
Answered R' A"E that when they cause the woman to lose her Ksuba that is not considerd a punishment but rather since she was unfaithful, the obligation of the husband to pay the Ksuba is automatically erased. Not a punishment but a consequence. So it turns out that the עדים didn't attempt to make the woman liable to two רשעיות [punishments for one sin]. That is different than the case Tosfos discusses of מוציא שם רע when they wanted to obligate the husband in two punishments [מלקות and ממון]. In that case they in fact receive both punishments.
We see from R' A"E that he understood Tosfos according to the first explanation we offered, that since they schemed to obligate the husband in a monetary penalty that is not exempted by קים ליה בדרבה מיניה, they also receive that liability and there is no קלב"מ for them either. And that is what he answered by saying that the woman is not liable to two punishments, so the עדים aren't obligated in the monetary liability. The rule of זממה is that it obligates in punishments and not automatic consequences.
However, based on our understanding that is not what Tosfos meant at all but rather that מלקות of הזמה is not given as a punishment but rather as המשכת החיוב - the drawing of the obligation of the falsely accused on to the accuser and therefore these מלקות don't have the status of "רשעה" [punishment] that would exempt them from the monetary payment.
But for that very reason R' A"E's question is not difficult because this principle we established relates only to מלקות where we can say that it is not a punishment but מיתה always has the status of "תורת דיני נפשות" and always exempts the lesser punishment. This is because permitting Jewish blood to be spilled is always defined as דיני נפשות and we can't call it המשכת החיוב [because of its severity?]. If so, whenever the blood of a Jew is permitted to be spilled it has the status of רשעה and thus exempts a lesser punishment.
The proof is that a רודף is פטור from ממון even though he does not receive the punishment of מיתת בית דין but rather anyone can kill him. It must be that the very fact that he must die is what exempts him because any permission to spill Jewish blood has the status of דיני נפשות. We also see this in the Yerushalmi that a בן סורר ומורה who is sentenced to death for his thievery is exempted from the monetary payment. Now the בן סורר ומורה is not killed as a punishment but "על שם סופו" - because of the sinful future that we envision for him, so why is he פטור from ממון? It must be that a Jew can't "סתם" have a דין that he must be killed but rather it must be subsumed under the more formal חיוב מיתה or דיני נפשות and thus has the status of a punishment which would exempt him from monetary payment [note - Rav Chaim Halevi disagrees. See the end of the 6th perek of Geirushin]. Due to this, we cannot say that עדים זוממין are both killed and pay because מיתה always creates a מצב of קים ליה בדרבה מיניה and is always considered "דיני נפשות". So we can understand why the witnesses of the husband are killed and don't pay, as the gemara says.
[עפ"י תורת הגאון רבי חיים שמואלביץ זצ"ל]
