Yes but had there been DRS, Taufeeq would have been reprieved and Gul gotten his 3 wickets so right now we are being heavily punished for the Sri Lankan board not being able to afford DRS!
Elite level umpires should be competent enough to make correct decisions most of the time without relying on DRS.
What we have seen are some shocking howlers from the officials that starts to question the credibility of Davis, and particularly Gould.