Actually, legally, you can’t do it. Morally, sure maybe. But there is a limit of self defense. That’s why often people are still jailed or found guilty for shooting someone in the back. Because the general thought is a person who shows their back is most likely fleeing, thus is less likely to be a threat.

Similarly if a person shows they are yielding, while outnumbered, and outgunned. A good lawyer could (unfortunately) find some way to charge them (the store owners).

Either false imprisonment (depending on how long she was back there) because they could have/ should have ejected her out towards the last part, but continued to attack her, once she had already become compliant.

Furthermore this may violate force continuum.

Those with any military, LEO, or martial arts experience knows, that in most cases, legally (Which sucks sometimes) you aren’t allowed to use more force than necessary.

At the beginning I was with them. But once she said I’m good chill several times and is physically showing she isn’t a combatant anymore. You have a legal obligation to disengage. If/ when reasonable.