I'll give you my take on why the intentional was a good option and also what are the escape options that may be available.
Taking the intentional was a two fold decision. One being that he had to get over his inning due to the complexity it presented.( in terms of any thing aggressive being available.) Which was evidenced by the option Palmer chose. Two being that the ending position with your option will possibly lure your opponent into making a bad decision with his return option. Like I mentioned in an earlier post that there are times when your opponent will try to execute a semi difficult shot from a seemingly tough position when he may not need to, when all he needs to do is take an intentional back. Don't forget you're on the first scratch, however, things don't always come down the way you think they should and at times you may get pleasantly surprised with your ..surprising opportunity off of a mistake in judgement by your opponent.
Return options would vary depending on where in the stack you're left in. In this situation you would look to see if the 13ball passes the 6ball, and if it is confirmed that the 13ball doesn't pass you would then have the top left corner available as an option with the cue ball. If it does pass then you need to look else where for an escape route. But don't forget that your opponent is on the first scratch and you shouldn't try to force a shot just to save a ball when the intentional back would be the best option. Reyes will still have the advantage..only in terms of winning the first move, because you're on the first scratch, however, the ball position still favors you and will obviously be the next battle you'll have in trying to preserve it...Great game it is..One Pocket. Interesting stuff.
Dr. Bill