Early BudJones coin-inlay chips had black lettering on the coin. I don't have a Rendezvous to compare with, but this appears from the scan to be one made with black lettering that lost the paint on one side. It appears you can see remnants in some of the letters, but this could be reflections in the scan. This kind of question can only be resolved by seeing the chip itself.

You sometimes find 'black letter' Desert Inn coin-inlays with the black paint coming off.

However, I wouldn't consider it a particularly valuable error even if the two coins are different. During a transition in production, the maker could easily have mixed the coins before the two sides were bonded and the coins inlaid.