blocking the basepath

Question
this pertains to the question previously answered july 30 ie Runner on 1st and 3rd with 1 out.  Batter hits a ground ball to the third baseman - runner on third runs home on contact.  Third baseman throws home and catcher is blocking the plate, the runner beats the throw (does not slide, but avoids contact with the catcher).  Runner's momentum takes him over the catcher and the umpire signals "safe" - then the catcher tags runner and umpire calls him out.  Umpire stated that a call had to be made when runner past home plate and stated that the runner did not touch home plate.  Should the umpire have made any signal?  The runner never made an attempt to go back to touch base because of the umpire's original call.
i thought that the play would end with an obstruction call on the catcher and the runner would be safe regardless.

Answer
Hi sbalser,

I briefly considered that but I wasn't there and the OP made no mention that there may have been obstruction and most players recognize what it is.  The PU didn't call it either. If we have obstruction we don't use a "safe" call but rather "dead ball" which didn't happen here.

My sense of his question was the "safe" then "out".  I just gave them the proper mechanic which the umpire seemed to have.  

Mark