Vayikra A morally inspiring comment, whose psychological kernel is eternally true. Fortunate is the generation whose leader is concerned to bring an atonement for his inadvertent sins, all the more so would he regret his intentional sins. From that pun it is a short leap to the moral lesson about the humble, honest prince. Rashi does not usually cite a midrash unless there is some problem with the Torah's words.
Similar verses appear in our sedra.
Rashi was sensitive to this deviation from the usual language used in this sedra. The Prince, being the highest authority in the community, had no one above him to fear. He was the apex of communal power. This is a unique situation. The ordinary citizen, even the virtuous one, lives in constant awareness, albeit unconscious, that if he is caught at a misdeed, he may be personally punished and publicly embarrassed.