The NIV doesn't always translate the word 'Hebrew' as 'Aramaic'.
It doesn't do so in Rev.9:11 and 16:16.
Great point!!! Let's read one of them:
"And they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon." [Rev 9:11]
That word "abaddon" comes directly out of the Biblical Hebrew, and from the Biblical Hebrew word "abaddown" meaning "destruction" and is found in Biblical Hebrew passages such as Esther 9:5, Job 26:6, 31:12, Psalm 88:11, Proverbs 15:11, 27:20.
Therefore, when John is using the word "Hebraisti" [Hebrew], as the inscription on the cross, he must mean Hebrew from the same source -- as if there is any other.