A hunting buddy of mine took a head on shot, on a small Ca forkie. His buck ran about 30yds and fell over dead. I say it depends on how “head on” it looked to me. I suppose it would have to be more of an “angling towards” shot before I would have. A straight head on, I don’t think I would have either. With a rifle, and then a neck shot,yes not a bow.
Either way, you were uncomfortable with the shot, so you absolutely made the right choice. I will not take an iffy shot even with a rifle. I want a clean, quick, humane kill.
If no more show up, at least you do not lose sleep because of the wounded deer you never found. Happens enough even with high percentage shots. No sense pressing our luck.