Leviticus 4: Taking responsibility

Chapter 4 discusses a rarity—leaders taking responsibility for their actions. The Torah lists three possible scenarios where a leader must bring a communal offering.
The first is a priest that makes a mistake. “If it is the anointed priest who incurred guilt, so that blame falls upon the people, he shall offer for the sin of which he is guilty a bull of the herd without blemish as a sin offering to the LORD” (Leviticus 4:3–4).
אִם־הַכֹּהֵן הַמָּשִׁיחַ יֶחֱטָא לְאַשְׁמַת הָעָם וְהִקְרִיב עַל־חַטָּאתוֹ אֲשֶׁר חָטָא פַּר בֶּן־בָּקָר תָּמִים לַה׳ לְחַטָּאת׃ וְהֵבִיא אֶת־הַפָּר אֶל־פֶּתַח אֹהֶל מוֹעֵד לִפְנֵי ה׳׃
The priest must have made an unwitting wrong decision and acted on that decision. The bull must be presented in front of the Mishkan and only then brought inside. It is interesting that in this case we have a bull as the offering a high priest must bring. The Torah usually tries to avoid a reminder of the sin of the Golden Calf with communal offerings, but perhaps the connection between Aaron’s mistake with the Golden Calf made this a necessity.
The second korban is brought by the entire community. “If it is the whole community of Israel that has erred and the matter escapes the notice of the congregation, so that they do any of the things which by the LORD’s commandments ought not to be done, and they realize their guilt… the congregation shall offer a bull of the herd as a sin offering” (Leviticus 4:13–14).
וְאִם כָּל־עֲדַת יִשְׂרָאֵל יִשְׁגּוּ וְנֶעְלַם דָּבָר מֵעֵינֵי הַקָּהָל וְעָשׂוּ אַחַת מִכָּל־מִצְוֹת ה׳ אֲשֶׁר לֹא־תֵעָשֶׂינָה וְאָשֵׁמוּ׃ וְנָתְנוּ הַקָּהָל פַּר בֶּן־בָּקָר לְחַטָּאת וְהֵבִיאוּ אֹתוֹ לִפְנֵי אֹהֶל מוֹעֵד׃
Again, a bull is brought in front of the Mishkan for all to see. The bull is used as the communal offering most likely as a stark reminder to the people of the danger of mistakes by the community.
The third case is when a prince/ruler makes a mistake. “When a chieftain sins and unwittingly does any of the things which by the LORD’s commandments ought not to be done, and he realizes his guilt… he shall bring as his offering a male goat without blemish” (Leviticus 4:22–23).
אֲשֶׁר נָשִׂיא יֶחֱטָא וְעָשָׂה אַחַת מִכָּל־מִצְוֹת ה׳ אֱלֹהָיו אֲשֶׁר לֹא־תֵעָשֶׂינָה בִּשְׁגָגָה וְאָשֵׁם׃ אוֹ הוֹדַע אֵלָיו חַטָּאתוֹ אֲשֶׁר חָטָא בָּהּ וְהֵבִיא אֶת־קָרְבָּנוֹ שְׂעִיר עִזִּים זָכָר תָּמִים׃
Ibn Ezra explains that a goat walks with its head held up in a haughty manner. The message to the ruler is that they are not above the law and must be careful not to walk in such a haughty manner. It may be that communal aspect of the sign by the leader requires them to bring such a public offering.