how do you know it was a clean miss?
as if you DON"T know if it hit high or low, you have NO clue where the bullet went correct?
which means it could have HIT the buck/deer in a NON vital area, and NOT all hits leave blood trails easy to see or find!
DID you look for the deer much?
and as stated, a miss can happen with a properly sighted in rifle, just as one not! things happen, and doesn;t take much of a movement to be off on target, as I doubt you were shooting of a bench when you fired at the deer, so that means human error can happen a LOT easier then when off a bench!
so, IF it really was a clean miss(and that normally means you seen where impact was and NO where near the animal, thus knowing 100% that it was a MISS)
then odds are it was human error, as even if bullet impact as to where sighted in,was off an inch up or down or likes, , at that range
a deer if aiming at its vitals, heart lung area, is a much larger area and should have been impacted at some point if your aim was true!
and I am NOT bashing you here either, I am just stating the fact, only way something is a CLEAN miss, is if you KNOW where your bullet landed,
as , others wise, you MAY have hit this deer!
its NOT uncommon for a rifle shot deer to NOT bleed or show signs of a hit for a few hundred yards!
I found many dead deer a few days or weeks later, that , shooters CLAIMED they missed, !
I Also shot and put several wounded one's down wasting my tag along the yrs due to poor hits they happen! (again NOT bashing just saying)