Olympian Michael Phelps’ highly promoted race with a great white shark on the kickoff to Discovery’s Shark Week programming Sunday night has drawn Twitter outrage from some disappointed viewers.

Nearly an hour into the Shark After Dark, program scientist and ecologist Tristan Gutteridge was heard saying “Clearly, we can’t put Michael in one lane and a white shark on the far lane. We’re gonna have to do a simulation.”

In Discovery’s press release promo-ing the Sunday night program, the episode was described as such: “Tony Hale and award-winning shark cinematographer Joe Romeiro discuss the most interesting race of Michael Phelps’ career, against a great white.”

Now common sense would probably indicate that Phelps wasn’t actually going to go fin-to-fin in a pool with a shark in an adjacent lane, and in pre-show interviews Phelps had made clear that would not be the case. The special showed an animated shark superimposed on the footage beside Phelps. But there were plenty of angry viewers who expected otherwise.

By the way, the computer-simulated shark won by two seconds. It clocked in at 36.1 seconds and Phelps, wearing a special swimsuit and fin, swam the distance in 38.1 seconds.

Here’s a sampling of viewer tweets: