Another interpretation: he asked the angels who surrounded him whether the man was fit to be killed, as it is written, "This one says thus and that one says thus" [the angels debating, one saying "thus" and the other "thus"].
Moses Asks the Surrounding Angels If the Egyptian Should Die
Yalkut Shimoni on Torah 167:4
דָּבָר אַחֵר, לַמַּלְאָכִים הַמַּקִּיפִין אוֹתוֹ שָׁאַל אִם רָאוּי לְהָרְגוֹ, דִּכְתִיב "זֶה בְּכֹה וְזֶה אֹמֵר בְּכֹה".