Yeah, Indiana shot 50% for the game but it was a blowout for three quarters so it's usual to relax and allow them to score more easily when all you've got to do is keep scoring... and with the way the offense was flowing last night (both with the starters and the 2nd unit), Indiana shooting 50% from the field was not a worrisome stat.
Also, I think the biggest difference in our good defense last night (leading to the start of the blowout in the 2nd quarter) was that Rondo did an excellent job of guarding his man, staying in front of him and fighting through screns. Thus, neither Ford nor Watson could penetrate easily and break down the C's defense for easy shots in the paint or wide open threes.
Really, if you watch the Memphis game again, you will see the difference between "good Rondo" and "gambling Rondo = terrible for our defense" since he played no defense against the Grizzlies but made the effort against Indiana.