When Krishna asks everyone what their conviction is different people say different things, but Arjuna says:
nimmantraNotsvah vipraah <-- brahmaNarige innobr mane oota chennaa
gavo navatrNotsvaah <-- cows are enthusiastic about fresh hay
bartharotsavah naryaah <-- wives are enthusiastic of spouses
aham krishna raNotsavah <-- for me it is war Krishna
So Krishna has taken Arjuna's conviction prior to the war, that Arjuna was interested in war but now he says Papam eva ashrayedh asman hatva atatayinah. But those who give punishment for an aparadhi then there is no papa attached. But one cannot determine an aparadhi by individual standards.
Draupadi says: purushaNam abhavena sarva naryah pativratah. If there were no men then all wives would be pati-vratas.
aatatataayin --- superior sinners; those who try to kill people by lighting house, poisons the other, illegally gobbles lands, kidnaps wife etc.
"tasman narha vayam hantum" -- now he says "vayam" (We), making a decision on behalf on his brothers (he seems like he is making decision on behalf of others on his side, but who is he to make that decision) or in other words he used the royal "We" to denote that is better than others.