LAST MISHNA CHAPTER 1 - "A SANHEDRIN THAT EXECUTES ONCE IN 7 [70] YEARS.." where the first part of the mishna deals with 2 different events [1) conviction in one court, escape, and return to same court; 2) conviction in one court, escape, and return to different court, and location of the different courts], why can't it be said that the rest of the mishna starting with "a sanhedrin that executes once in seven years is a destroyer" refers also to two events, and is a continuation of the first part of the mishna, such that it would refer to a situation where an escaped convicted person was returned to the court and gets executed without retrial.
Then, it could be understood to imply not that ANY executing court is a destroyer, but that a court that executes once in 7 [70] years, without a retrial, based on testimony that a person was previously sentenced, is a destroyer?
[and as addendum to makkos 10, much appreciation for helping isolated jews be able to get some protection of learning together]
gedaliah
This part of the Mishnah (which is separated from the first part of the Mishnah by the statement "Sanhedrin Noheges Ba'aretz u've'Chutz la'Aretz" is clearly referring to the neccesity for Beis Din to be calculated, as is evident from the statements of Rebbi Akiva and Rebbi Tarfon. This is the way all of the Rishonim explain the Mishnah.
D. Zupnik