After I read a story about Gio Urshela of the Yankees drawing a three-ball walk on Friday night, I went to Gameday's pitch-by-pitch data to see how it was rendered. It showed a four-ball walk.
Andrew Simon's story (mlb.com, oddly enough) included video of Urshela's plate appearance, which shows the number of pitches thrown by Detroit's Kyle Funkhouser increasing by one after each pitch. There are no pitches missing from the video.
From the sounds on the Yankees' broadcast, Urshela fouled off the fourth pitch into or near the first base camera well.