Cards laid moved peg

I have a questions about a situation we recently had playing crib.
My partner played his card then i played mine then his making 25. I said i couldn't go. He took his peg and moved it 1.
I was about to put my card down and he said 25 was the last i have a 6 so that will make 31 and peg 2 points.
I said a card laid is a card played and you already pegged your point.
Should i have allowed him to go back and play his card and move his peg?
I dont know what to do in a situation like this. Do you pick your card back up and allow who ever you are playing against to take back the moved peg lay their cards and the peg more?

It depends

The ACTUAL rule says that the player reneged on their play, as they should have played the 6 instead of taking the go. This was a mistake on that player's part. If you want to follow the rules as written, the player would take his point back and you would get two points for each card they could have played as a penalty for their error. Additionally, you can call the card that they should have played either dead or alive for the remaining of the pegging (not the count of their hand). It just depends how much you want to enforce the rule. You can view those rules at cribbage.org.