Theatre, equality... feh, too little meat and potatoes lately. I feel a need to reverse my slide and post something more substantive : )
The gemara writes (Makkos 6b) that eidus meyuchedes, i.e. each witness observes an act but is unaware of the other, is considered valid for dinei mamonos but not for dinei nefashos. The necessity for “two witnesses” means producing two witnesses aware of each other. “Maskif lah Mar Zutra”, the gemara asks, “m’atah b’dinei nefashos tatzil”? Meaning: if we have 1 witness and 1 witness in a capital crime, the principle of eidus meyuchedes serves as a leniency and the witnesses are not joined as a group of 2. But what if we have 2 witnesses and 2 witnesses who claim no knowledge of each other? Had we considered eidus meyuchedes valid, the 4 would become one single group. Had even one member of the 4 been pasul, all 4 would be thrown out. However, since eidus meyuchedes doesn't work, they are viewed as 2 and 2. If 1 witness is pasul, the accused can still be killed on the basis of the testimony of the other two. Since the Torah commands us to use every leniency at our disposal in capital cases, why not accept eidus meyuchedes just like in dinei mamonos for the sake of invalidating the entire group?
I did not understand this kashe when I learned it with my son. If eidus meyuchedes is invalid for dinei nefashos, how can we suddenly ignore the rules of testimony and accept it in order to spare the accused?
I think the answer is that the psul of eidus meyuchedes is not a din in hilchos eidus that says witnesses or testimony is invalid. It is a din in Bais Din, that the court cannot prosecute judgment on the basis of this type of eidus. However, “v’hitzilu haeidah” the command to try to save the accused, is also the responsibility of the Court. Where the Court faces conflicting responsibilities, the need to save the accused should win out over other priorities.