Question For Questioning People

The mishna at the beginning of Beitza cites a machlokes between Beis Shammai and Beis Hillel as to what the amount of chametz and se-or one is not allowed to own.


What is the nafka minah what the shiur is?? A chatzi shiur is ALSO assur min ha-torah so you are not allowed to own any chametz??


[The Rebbe Shlita in his weekly daf yomi bi-iyun shiur]