pretty bad? You are being way too generous.
Pretty bad is about accurate. He repeated things a number of times. For example, when Desmond was batting in the eighth, he mentioned at least twice that he was hit by a pitch in his previous at bat. His walkoff call was pretty good, though.
On another note, from ESPN: "The Nationals have three walk-off base hits this year, and all have been home runs (Mike Morse, Danny Espinosa, Wilson Ramos). Only two other teams (Oakland and the White Sox) have had all their walk-off hits come via the long ball, and they only have one each."