That's pretty cool! It's the kind of thing that you would never notice until someone points it out, but have a "Holy crap!" momment when you realsise what it could be continuity-wise.
In real-life, it was probably put their by the effects team as another scratch on the helmet to give it a more worn look.
Still, this could help solve the "How comew the first pred wasen't blooded" debate. Nice find!