Moshe Asked for Help
There are four instances in the Torah that we are taught that Moshe Rabbeinu forgot the Halacha and needed to ask Hashem for direction.
The קול התורה of Rav Elie Munk explained that Moshe thought he wasn’t able to be impartial, so he was not able to state the law.
The first instance was the story of the מקלל ה׳, the Blasphemer, who cursed Hashem. Some say he was the son of the Egyptian who raped Shlomit. This was the same Egyptian that was hitting a Jew. Moshe couldn’t be impartial because he killed the father of the מקלל ה׳. He was put to death.
Regarding פסח שני, Moshe thought it was a passing Mitzva and it was not for him to decide.
Regarding the inheritance of בנות צלפחד, Moshe felt that he couldn’t be objective, because צלפחד did not rebel with Korach. This could have clouded his objectivity.
Regarding the מקושש עצים, the one who gathered wood on Shabbat, Moshe forgot the law because he may have been too upset that just two weeks earlier, he taught the laws of Shabbat, and already it’s being violated.
Some say there could have been a fifth time when Pinchas killed Zimri and Kozbi, and Moshe forgot the law. This case was placed in its own separate category.
Even the great ones forget, and should not be ashamed to ask for help.