Could you please help me to understand what exactly is the case on Shabbos 3b: where the Gemara suggests that the two braitot are arguing in a case of where a guy picked something up either while it was still day (Erev Shabbos) or on Shabbos itself, and thus whether or not he should be forbidden to bring his arm back in as a punishment.
So the Gemara says that it would make sense if we only punish the guy to have to keep his hand outside all day only in a case where he stuck his hand outside (did the 'akira') on Erev Shabbos, because if he then comes to throw the object on Shabbos, he won't be chayav a chatas, whereas if he picked it up on Shabbos itself and we make him hold his hand outside and he throws it, he will be chayav a chatas.
My question (sorry if it's really obvious or easily found) is: What are the circumstances of him throwing the object? If he drops it from his arm getting tired, so even if he stuck his hand outside mishachasheichah (on Shabbos), then the fact he dropped it is only an oness because he had to keep his hand outside because of the issur/knas - so why should he be chayav a chatas?
And if he did it bemeizid after having stuck his hand outside on Shabbos itself, then why should he be chayav a chatas - he should be chayav skila/kareis?
Is it maybe that he was forced to hold his hand outside and he dropped it by accident, not because of tiredness? In which case this is anyway not a melechet machashevet, since he accidentally dropped the thing (?), so why is he chayav a chatas?
Thank you very much and Chanukah sameach
BH, London, UK
Shogeg as far as a Chatas is concerned means the person was unaware of the prohibition, as explained in Perek Klal Gadol (67b). The case would therefore be where he believed that he may drop it, perhaps because he mistakenly believed that he may put it down when his hand became very tired.