actually you can not appeal what you do is PROTEST

If that is true, than ,If I understand you correctly, that the ump saw the runner miss the bag, then called him safe and then will change his call if the defense noticed the runner missed the bag ? And if that is the case would the result be any different if this play was at the plate.

"that the ump saw the runner miss the bag, then called him safe"
why would the ump do that ?

Original post was

How about this play. I've seen it twice and called different ways. Batter hits ground ball to deep short. Runner clearly beats the throw but misses first base. No call from umpire, although the first baseman has ball in glove and foot on base. Runner walks back to base and umpire calls him safe.

Question is did the runner have possesion of first base even though he missed the bag? And does the fielder now have to TAG the runner to record the out?

The post does not say the umpire clearly saw the runner missed the base. Obviously the umpire did not see the runner missed the base (JUDGEMENT).

This seems to be getting very confusing. I know what the orig
post said, but my point was that if the ump calls him safe,then the ump thought he touched the base (In error, but still his call). If the ump saw him miss the bag, he will call him out because he missed the bag. There is no appeal here. Now I have seen some Little League games where the loudest screamer can make the ump change his mind, when the ump was not sure of what he saw. Human error cannot be factored in to this equation.
The orig post said he saw it called two ways, one was just wrong.