I was playing in a heads-up NL over the weekend, just friendly with a mate and had the following situation come up. Can I get someone's take on this please?

Small but generally committed pot has grown from both players through to the flop. This is where we join it.

TURN CARD COMES DOWN.

Villain (UTG): Pauses briefly to assess the board then announces RAISE.
Hero: Immediately cuts off the end of Villians word with "ALL IN!!"

At the point Villain announced RAISE, he had no chips in hand (though was about to head that way) and was not given the chance to announce the amount of the raise, as Hero cut them off before they could say how much. No chips have passed the line.

Has Hero acted out of turn? Villian never said how much they were going to raise, nor have they committed any chips to the pot, but Hero expects to earn off of the hand despite the fact that nobody has any idea if Villian was raising minimum, medium or huge.

What's your take?

Technically assuming it was the first action on the street villain should say bet and not raise so I am not 100% sure any bet would even be binding in the casino but going on intent then he should now be allowed to determine his betsize. That can obviously be anything from the minimum allowed bet or more. Hero's all in then stands.