I think the Facebook post is neutral to good for him as he only mentions “an offer” as opposed to a scholarship and made it clear he only applied to Yale. It is plausible that he meant the General and the MOH recipients assured him they could get him in.
The “Gifted Hands” quote would seem to be far more problematic as he mentioned acceptance and a scholarship.
Carson did not write in Gifted Hands that he was accepted to West Point.