The parsha begins with the mitzvah of appointing judges & law enforcement agents & it ends with egla arufah.
In the middle there is the mitzvos of kings, one of them being Lo Yarbeh lo Noshim. We are familiar with the medrash that the Yud of Yarbeh complained to Hashem about Shlomoh's transgression.
There is a simple question here as to why specifically the YUD complained.
The Maharil diskin offers a unique understanding to Shomoh HaMelech's mistake. Shlomoh understood that this prohibition, being said in a 'third person' tense - 'lo Yarbeh' as opposed to 'lo Tarbeh' - is really upon Beis Din - and not to the king himself. The King may focus on the greatness of the royalty, while Beis Din has the mitzvah to keep him 'in check'.
His grave error was erroneously placing responsibility for his deeds upon others.
(the true reason for the Yud, the Maharil explains, is because there was no king for the Torah to speak to directly.)
This seems to be the chut ham'shulash in this parshah, as the Chidah explains the lashon yachid in the beginning of the parsha - titen l'cha ... That the Torah demands each person to be on guard for himself.
Egla arufah is clearly the parshah of accepting fault, as the leaders of the closer city ask forgiveness for the person's death.
