Here is one way by which the defender can move forward or backward during a "misunderstanding" that has turned violent.

Start off in the Aikido stance.

Move your front foot forward while maintaining you balance.

Then move your hips forward.

Draw your rear foot in. Moving your hips forward to constantly maintain balance.

Depending on how close you drew your rear foot in, you can adjust yourself by moving you right foot forward.

Get back in to the Aikido stance.

This movement always keeps you facing the same direction. You can use this motion if your opponents are all on the same side of you.

Through out the motion your guard should always be up.