Runner interference versus umpire interference

[Jay R]

Are there any differences regarding runner int. versus umpire interference in the following example?

R2 is struck by a batted ball that has passed the 3B but the SS still has a play on the ball, this is interference on R2.

U3 is struck by a batted ball that has passed the 3B but the SS still has a play on the ball. Is this also umpire interference or is the rule different when it applies to umpires?

Thanks.