I imagine it would be seen as having left (given up your ground) and then returned thereby entering the other person's ground. I'm pretty sure even without stand yiur ground if you are in an altercation, leave, and return, it's seen as you are now the aggressor.

I've seen this happen with fights without weapons involved (both in real life and shows like Live PD), and the charges are always serious if they left and came back, most especially with a weapon.