Show me another example of this in the Bible. Then you can also explain to me why every reputable Bible translates the verse as "heard" and only the NIV as "understood?"
Am I being blatantly inconsistent”?
Yes, imo.
The World English Bible, The NwT, The Int. Standard Bible, but then I’ve not researched ALL translations.
Robertson’s Word Pictures in the New Testament comments:
“Acts 22:9
But they heard not the voice (thn de fwnhn ouk hkousan). The accusative here may be used rather than the genitive as in verse Acts 22:7 to indicate that those with Paul did not understand what they heard (Acts 9:7) just as they beheld the light (Acts 22:9), but did not see Jesus (Acts 9:7). The difference in cases allows this distinction, though it is not always observed as just noticed about Acts 22:14; Acts 26:14. The verb akouw is used in the sense of understand (Mark 4:33; 1 Corinthians 14:2). It is one of the evidences of the genuineness of this report of Paul’s speech that Luke did not try to smooth out apparent discrepancies in details between the words of Paul and his own record already in ch. 9. The Textus Receptus adds in this verse: “And they became afraid” (kai emfoboi egenonto). Clearly not genuine.
www.bibletools.org/index.cfm//fuseaction/Bible.show/.../
Another example of idiomatic language that is similar?
The words of Jesus at Matt. 7:23. He says, ‘Get away from me, I NEVER KNEW you’. But if he did not “Know” those he was speaking to, how would he know they were workers of lawlessness?