As a source for how we know that Eideem Zomemeem don't have to go to Galut, R'Yochanan offers the following KvC: If a person who even commits an action is not sent to Galut, KvC Edeem Zomemeem who didn't commit an action should not be sent to Galut! He is making the assumption that we are never more stringent with someone who doesn't commit an acion than someone who does commit an action.
However, how can he ever make that assumption! Everyone agrees that Edeem Zomemeem can be KILLED, the strictest form of punishment there is! Being killed is no doubt more harsh of a punishment (or at least equally harsh)than the punishment for many actions! This question has stumped me for a very long time. Thank you so much.
David Shamsi, Philadelphia, USA
There are two similar but disparate answers to your question. Rav Elchanan Wasserman in Kovetz Shiurim (vol. 1 Kesuvos note 107) explains that the punishment, which they caused to be wrongly placed on the convicted man, is transferred from the shoulders' of the convicted man and onto their own. Since the convicted man's Chiyuv is only applicable for Shogeg, it cannot be given to the Zomemim who were Mezid.
Rav Shmuel Rozovski was not entirely happy with this explanation. He preferred to say that the Chiyuv is their own Chiyuv, but Rebbi Yochanan is learning that the Chiyuv of Galus is unsuitable for a Mezid and can only be given for a Shogeg.
According to both answers, Rebbi Yochanan did not mean to learn from the Kal v'Chomer that an action must be more Chamur than a Ma'aseh, as you point out.
Dov Freedman