Beats me, but I suspect it was a timing issue. The Lord wasn't ready before then to have non-Israelites come into the church of God before this time. Therefore he didn't this sin of Peter's to him until this time.
If, in spite of all those years with Jesus, Peter didn't get the gentile connection correct, how do we know that he got the food issue correct?
I find it incredible that you're questioning Peter and what the Lord taught him. Granted Peter wasn't perfect, but it seems absurd that you would think that Peter was somehow too dense to understand what would have been a major doctrinal, cultural and lifestyle change.
It WAS not and IS not a teaching of Christ that the scriptural food laws the Christ created are done away with. It simply wasn't done.
And I say it was, and most scholars agree with me.
I feel confident in believing Peter, someone who was actually there and offered up his testimony in holy scripture.
Paul was a pharisee of the pharisees...it took him 14 years to understand the church of one body, Jew and Gentile...it wasn't an easy doctrinal issue for Peter to learn quickly.
But somehow Peter violated Jewish law and tradition by living after the manner of Gentiles.
His down fall wasn't living after the manner of Gentiles, it was going back to the law and traditions.