If your arrow has gone through the windpipe there is a dead deer out there that needs your tag.
That being said, if you did hit the windpipe your arrow would have almost certainly hit some major blood vessels, causing some severe blood loss. All the bleeding would most likely be external. If you watched him walk away, and the path he took did not have blood, it was probably a superficial wound.
His lack of reaction is not a good indicator of how severe the hit was, and with a neck hit neither is your arrow. If you did hit some major blood vessels, the bleeding will not stop, and the deer will die. If it were me, at daylight, I would do a search in the most likely direction he took. If the wound was severe, and you did not push him, he will not be far from the last place you saw him. Good luck. I hope this helps.