I got in one of those Muley/Whitetail crosses the other day.... Heavy striped tail with a black tip, Whitetail antlers HUGE body with tiny antlers. and it looked much more like a blacktail.... So I would say that Blacktails are the hybrids... not mulies... But that's just my 2 cents... Maybe the DNA tells a different story...
Sounds like a mule deer, with a small rack to me.