Situation: Runner on 2nd base. Ball is hit to SS. Runner slows down to let ss pass infront but then the ss steps back one step, runner then continues to 3rd base. No contact occured. Ruling by the umpire at home and confirmed by the field umpire is that the runner caused the fielder to change direction, therefore she is out for interference.

Please tell me your thoughts about this situation.

I'm not understanding how the runner forced this change in the SS's direction in this situation? However, if in the umpire's judgement, this happened - "Dead Ball", runner out for interference. What happened after the SS's step backward? Did she field the ball? Was she somehow impeded in either catching the ball or making the throw to first or third?

If the SS stepped back, it sounds more like it was an attempt to draw an INT call.

The runner stopped to allow the SS to field the ball. If the SS goes in the opposite direction, this is nothing more than a DMF.

I don't see interference here. A runner can run in front of, behind, and even stop to allow the defensive player an attempt to field the ball, which is what the runner did. Plus, there was no contact and the runner didn't force the defensive player out of the play.

I concur, this seems like it was a no call situation. From the description, it sounds like the defensive player made a choice to make the play in a location one step back from where they were. I don't see how the runner impacted this decision.

IMO, players have choices. On offense, a runner may choose to slide directly into a bag or make a sweep slide for the back of the bag. You only have obstruction if the defense took away one of the runners choices by impeding their way to a portion of the bag. The defense may charge the ball or let it come to them. It can only be interference if the offense took away one of the defensive players choices to make a play.